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Javascript operators are used to perform different types of mathematical and logical computations.

The Assignment Operator = assigns values

The Addition Operator + adds values

The Multiplication Operator * multiplies values

The Comparison Operator > compares values

JavaScript Assignment

The Assignment Operator ( = ) assigns a value to a variable:

Assignment Examples

Javascript addition.

The Addition Operator ( + ) adds numbers:

JavaScript Multiplication

The Multiplication Operator ( * ) multiplies numbers:

Multiplying

Types of javascript operators.

There are different types of JavaScript operators:

  • Arithmetic Operators
  • Assignment Operators
  • Comparison Operators
  • String Operators
  • Logical Operators
  • Bitwise Operators
  • Ternary Operators
  • Type Operators

JavaScript Arithmetic Operators

Arithmetic Operators are used to perform arithmetic on numbers:

Arithmetic Operators Example

Operator Description
+ Addition
- Subtraction
* Multiplication
** Exponentiation ( )
/ Division
% Modulus (Division Remainder)
++ Increment
-- Decrement

Arithmetic operators are fully described in the JS Arithmetic chapter.

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JavaScript Assignment Operators

Assignment operators assign values to JavaScript variables.

The Addition Assignment Operator ( += ) adds a value to a variable.

Operator Example Same As
= x = y x = y
+= x += y x = x + y
-= x -= y x = x - y
*= x *= y x = x * y
/= x /= y x = x / y
%= x %= y x = x % y
**= x **= y x = x ** y

Assignment operators are fully described in the JS Assignment chapter.

JavaScript Comparison Operators

Operator Description
== equal to
=== equal value and equal type
!= not equal
!== not equal value or not equal type
> greater than
< less than
>= greater than or equal to
<= less than or equal to
? ternary operator

Comparison operators are fully described in the JS Comparisons chapter.

JavaScript String Comparison

All the comparison operators above can also be used on strings:

Note that strings are compared alphabetically:

JavaScript String Addition

The + can also be used to add (concatenate) strings:

The += assignment operator can also be used to add (concatenate) strings:

The result of text1 will be:

When used on strings, the + operator is called the concatenation operator.

Adding Strings and Numbers

Adding two numbers, will return the sum, but adding a number and a string will return a string:

The result of x , y , and z will be:

If you add a number and a string, the result will be a string!

JavaScript Logical Operators

Operator Description
&& logical and
|| logical or
! logical not

Logical operators are fully described in the JS Comparisons chapter.

JavaScript Type Operators

Operator Description
typeof Returns the type of a variable
instanceof Returns true if an object is an instance of an object type

Type operators are fully described in the JS Type Conversion chapter.

JavaScript Bitwise Operators

Bit operators work on 32 bits numbers.

Operator Description Example Same as Result Decimal
& AND 5 & 1 0101 & 0001 0001  1
| OR 5 | 1 0101 | 0001 0101  5
~ NOT ~ 5  ~0101 1010  10
^ XOR 5 ^ 1 0101 ^ 0001 0100  4
<< left shift 5 << 1 0101 << 1 1010  10
>> right shift 5 >> 1 0101 >> 1 0010   2
>>> unsigned right shift 5 >>> 1 0101 >>> 1 0010   2

The examples above uses 4 bits unsigned examples. But JavaScript uses 32-bit signed numbers. Because of this, in JavaScript, ~ 5 will not return 10. It will return -6. ~00000000000000000000000000000101 will return 11111111111111111111111111111010

Bitwise operators are fully described in the JS Bitwise chapter.

Test Yourself With Exercises

Multiply 10 with 5 , and alert the result.

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Exercise 1 »   Exercise 2 »   Exercise 3 »   Exercise 4 »   Exercise 5 »

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  • Assignment operators

An assignment operator assigns a value to its left operand based on the value of its right operand.

The basic assignment operator is equal ( = ), which assigns the value of its right operand to its left operand. That is, x = y assigns the value of y to x . The other assignment operators are usually shorthand for standard operations, as shown in the following definitions and examples.

Name Shorthand operator Meaning

Simple assignment operator which assigns a value to a variable. The assignment operation evaluates to the assigned value. Chaining the assignment operator is possible in order to assign a single value to multiple variables. See the example.

Addition assignment

The addition assignment operator adds the value of the right operand to a variable and assigns the result to the variable. The types of the two operands determine the behavior of the addition assignment operator. Addition or concatenation is possible. See the addition operator for more details.

Subtraction assignment

The subtraction assignment operator subtracts the value of the right operand from a variable and assigns the result to the variable. See the subtraction operator for more details.

Multiplication assignment

The multiplication assignment operator multiplies a variable by the value of the right operand and assigns the result to the variable. See the multiplication operator for more details.

Division assignment

The division assignment operator divides a variable by the value of the right operand and assigns the result to the variable. See the division operator for more details.

Remainder assignment

The remainder assignment operator divides a variable by the value of the right operand and assigns the remainder to the variable. See the remainder operator for more details.

Exponentiation assignment

This is an experimental technology, part of the ECMAScript 2016 (ES7) proposal. Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future version of browsers as the spec changes.

The exponentiation assignment operator evaluates to the result of raising first operand to the power second operand. See the exponentiation operator for more details.

Left shift assignment

The left shift assignment operator moves the specified amount of bits to the left and assigns the result to the variable. See the left shift operator for more details.

Right shift assignment

The right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the right shift operator for more details.

Unsigned right shift assignment

The unsigned right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the unsigned right shift operator for more details.

Bitwise AND assignment

The bitwise AND assignment operator uses the binary representation of both operands, does a bitwise AND operation on them and assigns the result to the variable. See the bitwise AND operator for more details.

Bitwise XOR assignment

The bitwise XOR assignment operator uses the binary representation of both operands, does a bitwise XOR operation on them and assigns the result to the variable. See the bitwise XOR operator for more details.

Bitwise OR assignment

The bitwise OR assignment operator uses the binary representation of both operands, does a bitwise OR operation on them and assigns the result to the variable. See the bitwise OR operator for more details.

Left operand with another assignment operator

In unusual situations, the assignment operator (e.g. x += y ) is not identical to the meaning expression (here x = x + y ). When the left operand of an assignment operator itself contains an assignment operator, the left operand is evaluated only once. For example:

Specifications

Specification Status Comment
Draft  
Standard  
Standard  
Standard Initial definition.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
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  • Arithmetic operators

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JAVASCRIPT ASSIGNMENT OPERATORS

In this tutorial, you will learn about all the different assignment operators in javascript and how to use them in javascript.

Assignment Operators

In javascript, there are 16 different assignment operators that are used to assign value to the variable. It is shorthand of other operators which is recommended to use.

The assignment operators are used to assign value based on the right operand to its left operand.

The left operand must be a variable while the right operand may be a variable, number, boolean, string, expression, object, or combination of any other.

One of the most basic assignment operators is equal = , which is used to directly assign a value.

javascript assignment operator

Assignment Operators List

Here is the list of all assignment operators in JavaScript:

In the following table if variable a is not defined then assume it to be 10.

Operator Description Example Equivalent to
= a = 10 a = 10
+= a += 10 a = a + 10
-= a -= 10 a = a - 10
*= a *= 10 a = a * 10
/= a /= 10 a = a / 10
%= a %= 10 a = a % 10
**= a **= 2 a = a ** 2
<<= a <<= 1 a = a << 1
>>= a >>= 2 a = a >> 2
>>>= a >>>= 1 a = a >>> 1
&= a &= 4 a = a & 4
|= a |= 2 a = a | 2
^= a ^= 5 a = a ^ 5
&&= a &&= 3 a = a && 3
||= a ||= 4 a = a || 4
??= a ??= 2 a = a ?? 2

Assignment operator

The assignment operator = is the simplest value assigning operator which assigns a given value to a variable.

The assignment operators support chaining, which means you can assign a single value in multiple variables in a single line.

Addition assignment operator

The addition assignment operator += is used to add the value of the right operand to the value of the left operand and assigns the result to the left operand.

On the basis of the data type of variable, the addition assignment operator may add or concatenate the variables.

Subtraction assignment operator

The subtraction assignment operator -= subtracts the value of the right operand from the value of the left operand and assigns the result to the left operand.

If the value can not be subtracted then it results in a NaN .

Multiplication assignment operator

The multiplication assignment operator *= assigns the result to the left operand after multiplying values of the left and right operand.

Division assignment operator

The division assignment operator /= divides the value of the left operand by the value of the right operand and assigns the result to the left operand.

Remainder assignment operator

The remainder assignment operator %= assigns the remainder to the left operand after dividing the value of the left operand by the value of the right operand.

Exponentiation assignment operator

The exponential assignment operator **= assigns the result of exponentiation to the left operand after exponentiating the value of the left operand by the value of the right operand.

Left shift assignment

The left shift assignment operator <<= assigns the result of the left shift to the left operand after shifting the value of the left operand by the value of the right operand.

Right shift assignment

The right shift assignment operator >>= assigns the result of the right shift to the left operand after shifting the value of the left operand by the value of the right operand.

Unsigned right shift assignment

The unsigned right shift assignment operator >>>= assigns the result of the unsigned right shift to the left operand after shifting the value of the left operand by the value of the right operand.

Bitwise AND assignment

The bitwise AND assignment operator &= assigns the result of bitwise AND to the left operand after ANDing the value of the left operand by the value of the right operand.

Bitwise OR assignment

The bitwise OR assignment operator |= assigns the result of bitwise OR to the left operand after ORing the value of left operand by the value of the right operand.

Bitwise XOR assignment

The bitwise XOR assignment operator ^= assigns the result of bitwise XOR to the left operand after XORing the value of the left operand by the value of the right operand.

Logical AND assignment

The logical AND assignment operator &&= assigns value to left operand only when it is truthy .

Note : A truthy value is a value that is considered true when encountered in a boolean context.

Logical OR assignment

The logical OR assignment operator ||= assigns value to left operand only when it is falsy .

Note : A falsy value is a value that is considered false when encountered in a boolean context.

Logical nullish assignment

The logical nullish assignment operator ??= assigns value to left operand only when it is nullish ( null or undefined ).

assignment operator js

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  • Assignment operators

An assignment operator assigns a value to its left operand based on the value of its right operand.

The basic assignment operator is equal ( = ), which assigns the value of its right operand to its left operand. That is, x = y assigns the value of y to x . The other assignment operators are usually shorthand for standard operations, as shown in the following definitions and examples.

Name Shorthand operator Meaning

Simple assignment operator which assigns a value to a variable. Chaining the assignment operator is possible in order to assign a single value to multiple variables. See the example.

Addition assignment

The addition assignment operator adds the value of the right operand to a variable and assigns the result to the variable. The types of the two operands determine the behavior of the addition assignment operator. Addition or concatenation is possible. See the addition operator for more details.

Subtraction assignment

The subtraction assignment operator subtracts the value of the right operand from a variable and assigns the result to the variable. See the subtraction operator for more details.

Multiplication assignment

The multiplication assignment operator multiplies a variable by the value of the right operand and assigns the result to the variable. See the multiplication operator for more details.

Division assignment

The division assignment operator divides a variable by the value of the right operand and assigns the result to the variable. See the division operator for more details.

Remainder assignment

The remainder assignment operator divides a variable by the value of the right operand and assigns the remainder to the variable. See the remainder operator for more details.

Left shift assignment

The left shift assignment operator moves the specified amount of bits to the left and assigns the result to the variable. See the left shift operator for more details.

Right shift assignment

The right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the right shift operator for more details.

Unsigned right shift assignment

The unsigned right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the unsigned right shift operator for more details.

Bitwise AND assignment

The bitwise AND assignment operator uses the binary representation of both operands, does a bitwise AND operation on them and assigns the result to the variable. See the bitwise AND operator for more details.

Bitwise XOR assignment

The bitwise XOR assignment operator uses the binary representation of both operands, does a bitwise XOR operation on them and assigns the result to the variable. See the bitwise XOR operator for more details.

Bitwise OR assignment

The bitwise OR assignment operator uses the binary representation of both operands, does a bitwise OR operation on them and assigns the result to the variable. See the bitwise OR operator for more details.

Left operand with another assignment operator

In unusual situations, the assignment operator (e.g. x += y ) is not identical to the meaning expression (here x = x + y ). When the left operand of an assignment operator itself contains an assignment operator, the left operand is evaluated only once. For example:

Specifications

Specification Status Comment
ECMAScript 1st Edition. Standard Initial definition.
Standard  
Release Candidate  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
  • Arithmetic operators

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JavaScript Assignment Operators

JavaScript Assignment OperatorsExampleExplanation
=x = 15Value 15 is assigned to x
+=x += 15This is same as x = x + 15
-=x -= 15This is same as x = x – 15
*=x *= 15This is same as x = x * 15
/=x /= 15This is same as x = x / 15
%=x %= 15This is same as x = x % 15

JavaScript Assignment Operators Example

Javascript assignment operators example 2.

Home » JavaScript Tutorial » JavaScript Logical Assignment Operators

JavaScript Logical Assignment Operators

Summary : in this tutorial, you’ll learn about JavaScript logical assignment operators, including the logical OR assignment operator ( ||= ), the logical AND assignment operator ( &&= ), and the nullish assignment operator ( ??= ).

ES2021 introduces three logical assignment operators including:

  • Logical OR assignment operator ( ||= )
  • Logical AND assignment operator ( &&= )
  • Nullish coalescing assignment operator ( ??= )

The following table shows the equivalent of the logical assignments operator:

Logical Assignment OperatorsLogical Operators
x ||= yx || (x = y)
x &&= yx && (x = y)
x ??= yx ?? (x = y);

The Logical OR assignment operator

The logical OR assignment operator ( ||= ) accepts two operands and assigns the right operand to the left operand if the left operand is falsy:

In this syntax, the ||= operator only assigns y to x if x is falsy. For example:

In this example, the title variable is undefined , therefore, it’s falsy. Since the title is falsy, the operator ||= assigns the 'untitled' to the title . The output shows the untitled as expected.

See another example:

In this example, the title is 'JavaScript Awesome' so it is truthy. Therefore, the logical OR assignment operator ( ||= ) doesn’t assign the string 'untitled' to the title variable.

The logical OR assignment operator:

is equivalent to the following statement that uses the logical OR operator :

Like the logical OR operator, the logical OR assignment also short-circuits. It means that the logical OR assignment operator only performs an assignment when the x is falsy.

The following example uses the logical assignment operator to display a default message if the search result element is empty:

The Logical AND assignment operator

The logical AND assignment operator only assigns y to x if x is truthy:

The logical AND assignment operator also short-circuits. It means that

is equivalent to:

The following example uses the logical AND assignment operator to change the last name of a person object if the last name is truthy:

The nullish coalescing assignment operator

The nullish coalescing assignment operator only assigns y to x if x is null or undefined :

It’s equivalent to the following statement that uses the nullish coalescing operator :

The following example uses the nullish coalescing assignment operator to add a missing property to an object:

In this example, the user.nickname is undefined , therefore, it’s nullish. The nullish coalescing assignment operator assigns the string 'anonymous' to the user.nickname property.

The following table illustrates how the logical assignment operators work:

  • The logical OR assignment ( x ||= y ) operator only assigns y to x if x is falsy.
  • The logical AND assignment ( x &&= y ) operator only assigns y to x if x is truthy.
  • The nullish coalescing assignment ( x ??= y ) operator only assigns y to x if x is nullish.

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JavaScript operators are special symbols that perform operations on one or more operands (values). For example,

Here, we used the + operator to add the operands 2 and 3 .

JavaScript Operator Types

Here is a list of different JavaScript operators you will learn in this tutorial:

  • Arithmetic Operators
  • Assignment Operators
  • Comparison Operators
  • Logical Operators
  • Bitwise Operators
  • String Operators
  • Miscellaneous Operators

1. JavaScript Arithmetic Operators

We use arithmetic operators to perform arithmetic calculations like addition, subtraction, etc. For example,

Here, we used the - operator to subtract 3 from 5 .

Commonly Used Arithmetic Operators

Operator Name Example
Addition
Subtraction
Multiplication
Division
Remainder
Increment (increments by ) or
Decrement (decrements by ) or
Exponentiation (Power)

Example 1: Arithmetic Operators in JavaScript

Note: The increment operator ++ adds 1 to the operand. And, the decrement operator -- decreases the value of the operand by 1 .

To learn more, visit Increment ++ and Decrement -- Operators .

2. JavaScript Assignment Operators

We use assignment operators to assign values to variables. For example,

Here, we used the = operator to assign the value 5 to the variable x .

Commonly Used Assignment Operators

Operator Name Example
Assignment Operator
Addition Assignment
Subtraction Assignment
Multiplication Assignment
Division Assignment
Remainder Assignment
Exponentiation Assignment

Example 2: Assignment Operators in JavaScript

3. javascript comparison operators.

We use comparison operators to compare two values and return a boolean value ( true or false ). For example,

Here, we have used the > comparison operator to check whether a (whose value is 3 ) is greater than b (whose value is 2 ).

Since 3 is greater than 2 , we get true as output.

Note: In the above example, a > b is called a boolean expression since evaluating it results in a boolean value.

Commonly Used Comparison Operators

Operator Meaning Example
Equal to gives us
Not equal to gives us
Greater than gives us
Less than gives us
Greater than or equal to gives us
Less than or equal to gives us
Strictly equal to gives us
Strictly not equal to gives us

Example 3: Comparison Operators in JavaScript

The equality operators ( == and != ) convert both operands to the same type before comparing their values. For example,

Here, we used the == operator to compare the number 3 and the string 3 .

By default, JavaScript converts string 3 to number 3 and compares the values.

However, the strict equality operators ( === and !== ) do not convert operand types before comparing their values. For example,

Here, JavaScript didn't convert string 4 to number 4 before comparing their values.

Thus, the result is false , as number 4 isn't equal to string 4 .

4. JavaScript Logical Operators

We use logical operators to perform logical operations on boolean expressions. For example,

Here, && is the logical operator AND . Since both x < 6 and y < 5 are true , the combined result is true .

Commonly Used Logical Operators

Operator Syntax Description
(Logical AND) only if both and are
(Logical OR) if either or is
(Logical NOT) if is and vice versa

Example 4: Logical Operators in JavaScript

Note: We use comparison and logical operators in decision-making and loops. You will learn about them in detail in later tutorials.

More on JavaScript Operators

We use bitwise operators to perform binary operations on integers.

Operator Description Example
& Bitwise AND
| Bitwise OR
^ Bitwise XOR
~ Bitwise NOT
<< Left shift
>> Sign-propagating right shift
>>> Zero-fill right shift

Note: We rarely use bitwise operators in everyday programming. If you are interested, visit JavaScript Bitwise Operators to learn more.

In JavaScript, you can also use the + operator to concatenate (join) two strings. For example,

Here, we used the + operator to concatenate str1 and str2 .

JavaScript has many more operators besides the ones we listed above. You will learn about them in detail in later tutorials.

Operator Description Example
: Evaluates multiple operands and returns the value of the last operand.
: Returns value based on the condition.
Returns the data type of the variable.
Returns t if the specified object is a valid object of the specified class.
Discards any expression's return value.

Table of Contents

  • Introduction
  • JavaScript Arithmetic Operators
  • JavaScript Assignment Operators
  • JavaScript Comparison Operators
  • JavaScript Logical Operators

Video: JavaScript Operators

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JavaScript Assignment Operators

The assignment operators in JavaScript are used to assign values to the variables. These are binary operators. An assignment operator takes two operands , assigns a value to the left operand based on the value of right operand. The left operand is always a variable and the right operand may be literal, variable or expression.

An assignment operator first evaluates the expression and then assign the value to the variable (left operand).

A simple assignment operator is equal (=) operator. In the JavaScript statement "let x = 10;", the = operator assigns 10 to the variable x.

We can combine a simple assignment operator with other type of operators such as arithmetic, logical, etc. to get compound assignment operators. Some arithmetic assignment operators are +=, -=, *=, /=, etc. The += operator performs addition operation on the operands and assign the result to the left hand operand.

Arithmetic Assignment Operators

In this section, we will cover simple assignment and arithmetic assignment operators. An arithmetic assignment operator performs arithmetic operation and assign the result to a variable. Following is the list of operators with example −

Assignment Operator Example Equivalent To
= (Assignment) a = b a = b
+= (Addition Assignment) a += b a = a + b
-= (Subtraction Assignment) a -= b a = a – b
*= (Multiplication Assignment) a *= b a = a * b
/= (Division Assignment) a /= b a = a / b
%= (Remainder Assignment) a %= b a = a % b
**= (Exponentiation Assignment) a **= b a = a ** b

Simple Assignment (=) Operator

Below is an example of assignment chaining −

Addition Assignment (+=) Operator

The JavaScript addition assignment operator performs addition on the two operands and assigns the result to the left operand. Here addition may be numeric addition or string concatenation.

In the above statement, it adds values of b and x and assigns the result to x.

Example: Numeric Addition Assignment

Example: string concatenation assignment, subtraction assignment (-=) operator.

The subtraction assignment operator in JavaScript subtracts the value of right operand from the left operand and assigns the result to left operand (variable).

In the above statement, it subtracts b from x and assigns the result to x.

Multiplication Assignment (*=) Operator

The multiplication assignment operator in JavaScript multiplies the both operands and assign the result to the left operand.

In the above statement, it multiplies x and b and assigns the result to x.

Division Assignment (/=) Operator

This operator divides left operand by the right operand and assigns the result to left operand.

In the above statement, it divides x by b and assigns the result (quotient) to x.

Remainder Assignment (%=) Operator

The JavaScript remainder assignment operator performs the remainder operation on the operands and assigns the result to left operand.

In the above statement, it divides x by b and assigns the result (remainder) to x.

Exponentiation Assignment (**=) Operator

This operator performs exponentiation operation on the operands and assigns the result to left operand.

In the above statement, it computes x**b and assigns the result to x.

JavaScript Bitwise Assignment operators

A bitwise assignment operator performs bitwise operation on the operands and assign the result to a variable. These operations perform two operations, first a bitwise operation and second the simple assignment operation. Bitwise operation is done on bit-level. A bitwise operator treats both operands as 32-bit signed integers and perform the operation on corresponding bits of the operands. The simple assignment operator assigns result is to the variable (left operand).

Following is the list of operators with example −

Assignment Operator Example Equivalent To
&= (Bitwise AND Assignment) a &= b a = a & b
|= (Bitwise OR Assignment) a |= b a = a | b
^= (Bitwise XOR Assignment) a ^= b a = a ^ b

Bitwise AND Assignment Operator

The JavaScript bitwise AND assignment (&=) operator performs bitwise AND operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs bitwise AND on x and b and assigns the result to the variable x.

Bitwise OR Assignment Operator

The JavaScript bitwise OR assignment (|=) operator performs bitwise OR operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs bitwise OR on x and b and assigns the result to the variable x.

Bitwise XOR Assignment Operator

The JavaScript bitwise XOR assignment (^=) operator performs bitwise XOR operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs bitwise XOR on x and b and assigns the result to the variable x.

JavaScript Shift Assignment Operators

A shift assignment operator performs bitwise shift operation on the operands and assign the result to a variable (left operand). These are a combinations two operators, the first bitwise shift operator and second the simple assignment operator.

Following is the list of the shift assignment operators with example −

Assignment Operator Example Equivalent To
<<= (Left Shift Assignment) a <<= b a = a << b
>>= (Right Shift Assignment) a >>= b a = a >> b
>>>= (Unsigned Right Shift Assignment) a >>>= b a = a >>> b

Left Shift Assignment Operator

The JavaScript left shift assignment (<<=) operator performs left shift operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs left shift on x and b and assigns the result to the variable x.

Right Shift Assignment Operator

The JavaScript right shift assignment (>>=) operator performs right shift operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs right shift on x and b and assigns the result to the variable x.

Unsigned Right Shift Assignment Operator

The JavaScript unsigned right shift assignment (>>>=) operator performs unsigned right shift operation on the operands and assigns the result to the left operand (variable).

In the above statement, it performs unsigned right shift on x and b and assigns the result to the variable x.

JavaScript Logical Assignment operators

In JavaScript, a logical assignment operator performs a logical operation on the operands and assign the result to a variable (left operand). Each logical assignment operator is a combinations two operators, the first logical operator and second the simple assignment operator.

Following is the list of the logical assignment operators with example −

Assignment Operator Example Equivalent To
&&= (Logical AND Assignment) a &&= b a = a && b
||= (Logical OR Assignment) a ||= b a = a || b
??= (Nullish Coalescing Assignment) a ??= b a = a ?? b
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Assignment Operators

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JavaScript: Assignment Operators

An assignment operator assigns a value to its left operand based on the value of its right operand. The first operand must be a variable and basic assignment operator is equal (=), which assigns the value of its right operand to its left operand. That is, a = b assigns the value of b to a.  In addition to the regular assignment operator "=" the other assignment operators are shorthand for standard operations, as shown in the following table.

a +=b a = a + b Adds 2 numbers and assigns the result to the first.
a -= b a = a - b Subtracts 2 numbers and assigns the result to the first.
a *= b a = a*b Multiplies 2 numbers and assigns the result to the first.
a /=b a = a/b Divides 2 numbers and assigns the result to the first.
a %= b a = a%b Computes the modulus of 2 numbers and assigns the result to the first.
a<<=b a = a<<b Performs a left shift and assigns the result to the first operand.
a>>=b a = a>>b Performs a sign-propagating right shift and assigns the result to the first operand.
a>>>=b a = a>>>b Performs a zero-fill right shift and assigns the result to the first operand.
a&= b a = a&b Performs a bitwise AND and assigns the result to the first operand.
a^= b a = a^b Performs a bitwise XOR and assigns the result to the first operand.
a |=b a = a|b Performs a bitwise OR and assigns the result to the first operand.

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Learn JavaScript Operators – Logical, Comparison, Ternary, and More JS Operators With Examples

Nathan Sebhastian

JavaScript has many operators that you can use to perform operations on values and variables (also called operands)

Based on the types of operations these JS operators perform, we can divide them up into seven groups:

Arithmetic Operators

Assignment operators, comparison operators, logical operators.

  • Ternary Operators

The typeof Operator

Bitwise operators.

In this handbook, you're going to learn how these operators work with examples. Let's start with arithmetic operators.

The arithmetic operators are used to perform mathematical operations like addition and subtraction.

These operators are frequently used with number data types, so they are similar to a calculator. The following example shows how you can use the + operator to add two variables together:

Here, the two variables x and y are added together using the plus + operator. We also used the console.log() method to print the result of the operation to the screen.

You can use operators directly on values without assigning them to any variable too:

In JavaScript, we have 8 arithmetic operators in total. They are:

  • Subtraction -
  • Multiplication *
  • Remainder %
  • Exponentiation **
  • Increment ++
  • Decrement --

Let's see how these operators work one by one.

1. Addition operator

The addition operator + is used to add two or more numbers together. You've seen how this operator works previously, but here's another example:

You can use the addition operator on both integer and floating numbers.

2. Subtraction operator

The subtraction operator is marked by the minus sign − and you can use it to subtract the right operand from the left operand.

For example, here's how to subtract 3 from 5:

3. Multiplication operator

The multiplication operator is marked by the asterisk * symbol, and you use it to multiply the value on the left by the value on the right of the operator.

4. Division operator

The division operator / is used to divide the left operand by the right operand. Here are some examples of using the operator:

5. Remainder operator

The remainder operator % is also known as the modulo or modulus operator. This operator is used to calculate the remainder after a division has been performed.

A practical example should make this operator easier to understand, so let's see one:

The number 10 can't be divided by 3 perfectly. The result of the division is 3 with a remainder of 1. The remainder operator simply returns that remainder number.

If the left operand can be divided with no remainder, then the operator returns 0.

This operator is commonly used when you want to check if a number is even or odd. If a number is even, dividing it by 2 will result in a remainder of 0, and if it's odd, the remainder will be 1.

6. Exponentiation operator

The exponentiation operator is marked by two asterisks ** . It's one of the newer JavaScript operators and you can use it to calculate the power of a number (based on its exponent).

For example, here's how to calculate 10 to the power of 3:

Here, the number 10 is multiplied by itself 3 times (10 _ 10 _ 10)

The exponentiation operator gives you an easy way to find the power of a specific number.

7. Increment operator

The increment ++ operator is used to increase the value of a number by one. For example:

This operator gives you a faster way to increase a variable value by one. Without the operator, here's how you increment a variable:

Using the increment operator allows you to shorten the second line. You can place this operator before or next to the variable you want to increment:

Both placements shown above are valid. The difference between prefix (before) and postfix (after) placements is that the prefix position will execute the operator after that line of code has been executed.

Consider the following example:

Here, you can see that placing the increment operator next to the variable will print the variable as if it has not been incremented.

When you place the operator before the variable, then the number will be incremented before calling the console.log() method.

8. Decrement operator

The decrement -- operator is used to decrease the value of a number by one. It's the opposite of the increment operator:

Please note that you can only use increment and decrement operators on a variable. An error occurs when you try to use these operators directly on a number value:

You can't use increment or decrement operator on a number directly.

Arithmetic operators summary

Now you've learned the 8 types of arithmetic operators. Excellent! Keep in mind that you can mix these operators to perform complex mathematical equations.

For example, you can perform an addition and multiplication on a set of numbers:

The order of operations in JavaScript is the same as in mathematics. Multiplication, division, and exponentiation take a higher priority than addition or subtraction (remember that acronym PEMDAS? Parentheses, exponents, multiplication and division, addition and subtraction – there's your order of operations).

You can use parentheses () to change the order of the operations. Wrap the operation you want to execute first as follows:

When using increment or decrement operators together with other operators, you need to place the operators in a prefix position as follows:

This is because a postfix increment or decrement operator will not be executed together with other operations in the same line, as I have explained previously.

Let's try some exercises. Can you guess the result of these operations?

And that's all for arithmetic operators. You've done a wonderful job learning about these operators.

Let's take a short five-minute break before proceeding to the next type of operators.

The second group of operators we're going to explore is the assignment operators.

Assignment operators are used to assign a specific value to a variable. The basic assignment operator is marked by the equal = symbol, and you've already seen this operator in action before:

After the basic assignment operator, there are 5 more assignment operators that combine mathematical operations with the assignment. These operators are useful to make your code clean and short.

For example, suppose you want to increment the x variable by 2. Here's how you do it with the basic assignment operator:

There's nothing wrong with the code above, but you can use the addition assignment += to rewrite the second line as follows:

There are 7 kinds of assignment operators that you can use in JavaScript:

Name Operation example Meaning
Assignment
Addition assignment
Subtraction assignment
Multiplication assignment
Division assignment
Remainder assignment
Exponentiation assignment

The arithmetic operators you've learned in the previous section can be combined with the assignment operator except the increment and decrement operators.

Let's have a quick exercise. Can you guess the results of these assignments?

Now you've learned about assignment operators. Let's continue and learn about comparison operators.

As the name implies, comparison operators are used to compare one value or variable with something else. The operators in this category always return a boolean value: either true or false .

For example, suppose you want to compare if a variable's value is greater than 1. Here's how you do it:

The greater than > operator checks if the value on the left operand is greater than the value on the right operand.

There are 8 kinds of comparison operators available in JavaScript:

Name Operation example Meaning
Equal Returns if the operands are equal
Not equal Returns if the operands are not equal
Strict equal Returns if the operands are equal and have the same type
Strict not equal Returns if the operands are not equal, or have different types
Greater than Returns if the left operand is greater than the right operand
Greater than or equal Returns if the left operand is greater than or equal to the right operand
Less than Returns if the left operand is less than the right operand
Less than or equal Returns if the left operand is less than or equal to the right operand

Here are some examples of using comparison operators:

The comparison operators are further divided in two types: relational and equality operators.

The relational operators compare the value of one operand relative to the second operand (greater than, less than)

The equality operators check if the value on the left is equal to the value on the right. They can also be used to compare strings like this:

String comparisons are case-sensitive, as shown in the example above.

JavaScript also has two versions of the equality operators: loose and strict.

In strict mode, JavaScript will compare the values without performing a type coercion. To enable strict mode, you need to add one more equal = symbol to the operation as follows:

Since type coercion might result in unwanted behavior, you should use the strict equality operators anytime you do an equality comparison.

Logical operators are used to check whether one or more expressions result in either true or false .

There are three logical operators available in JavaScript:

Name Operation example Meaning
Logical AND Returns if all operands are , else returns
Logical OR Returns if one of the operands is , else returns
Logical NOT Reverse the result: returns if and vice versa

These operators can only return Boolean values. For example, you can determine whether '7 is greater than 2' and '5 is greater than 4':

These logical operators follow the laws of mathematical logic:

  • && AND operator – if any expression returns false , the result is false
  • || OR operator – if any expression returns true , the result is true
  • ! NOT operator – negates the expression, returning the opposite.

Let's do a little exercise. Try to run these statements on your computer. Can you guess the results?

These logical operators will come in handy when you need to assert that a specific requirement is fulfilled in your code.

Let's say a happyLife requires a job with highIncome and supportiveTeam :

Based on the requirements, you can use the logical AND operator to check whether you have both requirements. When one of the requirements is false , then happyLife equals false as well.

Ternary Operator

The ternary operator (also called the conditional operator) is the only JavaScipt operator that requires 3 operands to run.

Let's imagine you need to implement some specific logic in your code. Suppose you're opening a shop to sell fruit. You give a $3 discount when the total purchase is $20 or more. Otherwise, you give a $1 discount.

You can implement the logic using an if..else statement as follows:

The code above works fine, but you can use the ternary operator to make the code shorter and more concise as follows:

The syntax for the ternary operator is condition ? expression1 : expression2 .

You need to write the condition to evaluate followed by a question ? mark.

Next to the question mark, you write the expression to execute when the condition evaluates to true , followed by a colon : symbol. You can call this expression1 .

Next to the colon symbol, you write the expression to execute when the condition evaluates to false . This is expression2 .

As the example above shows, the ternary operator can be used as an alternative to the if..else statement.

The typeof operator is the only operator that's not represented by symbols. This operator is used to check the data type of the value you placed on the right side of the operator.

Here are some examples of using the operator:

The typeof operator returns the type of the data as a string. The 'number' type represents both integer and float types, the string and boolean represent their respective types.

Arrays, objects, and the null value are of object type, while undefined has its own type.

Bitwise operators are operators that treat their operands as a set of binary digits, but return the result of the operation as a decimal value.

These operators are rarely used in web development, so you can skip this part if you only want to learn practical stuff. But if you're interested to know how they work, then let me show you an example.

A computer uses a binary number system to store decimal numbers in memory. The binary system only uses two numbers, 0 and 1, to represent the whole range of decimal numbers we humans know.

For example, the decimal number 1 is represented as binary number 00000001, and the decimal number 2 is represented as 00000010.

I won't go into detail on how to convert a decimal number into a binary number as that's too much to include in this guide. The main point is that the bitwise operators operate on these binary numbers.

If you want to find the binary number from a specific decimal number, you can Google for the "decimal to binary calculator".

There are 7 types of bitwise operators in JavaScript:

  • Left Shift <<
  • Right Shift >>
  • Zero-fill Right Shift >>>

Let's see how they work.

1. Bitwise AND operator

The bitwise operator AND & returns a 1 when the number 1 overlaps in both operands. The decimal numbers 1 and 2 have no overlapping 1, so using this operator on the numbers return 0:

2. Bitwise OR operator

On the other hand, the bitwise operator OR | returns all 1s in both decimal numbers.

The binary number 00000011 represents the decimal number 3, so the OR operator above returns 3.

Bitwise XOR operator

The Bitwise XOR ^ looks for the differences between two binary numbers. When the corresponding bits are the same, it returns 0:

5 = 00000101

Bitwise NOT operator

Bitwise NOT ~ operator inverts the bits of a decimal number so 0 becomes 1 and 1 becomes 0:

Bitwise Left Shift operator

Bitwise Left Shift << shifts the position of the bit by adding zeroes from the right.

The excess bits are then discarded, changing the decimal number represented by the bits. See the following example:

The right operand is the number of zeroes you will add to the left operand.

Bitwise Right Shift operator

Bitwise Right Shift >> shifts the position of the bits by adding zeroes from the left. It's the opposite of the Left Shift operator:

Bitwise Zero-fill Right Shift operator

Also known as Unsigned Right Shift operator, the Zero-fill Right Shift >>> operator is used to shift the position of the bits to the right, while also changing the sign bit to 0 .

This operator transforms any negative number into a positive number, so you can see how it works when passing a negative number as the left operand:

In the above example, you can see that the >> and >>> operators return different results. The Zero-fill Right Shift operator has no effect when you use it on a positive number.

Now you've learned how the bitwise operators work. If you think they are confusing, then you're not alone! Fortunately, these operators are scarcely used when developing web applications.

You don't need to learn them in depth. It's enough to know what they are.

In this tutorial, you've learned the 7 types of JavaScript operators: Arithmetic, assignment, comparison, logical, ternary, typeof, and bitwise operators.

These operators can be used to manipulate values and variables to achieve a desired outcome.

Congratulations on finishing this guide!

If you enjoyed this article and want to take your JavaScript skills to the next level, I recommend you check out my new book Beginning Modern JavaScript here .

beginning-js-cover

The book is designed to be easy to understand and accessible to anyone looking to learn JavaScript. It provides a step-by-step gentle guide that will help you understand how to use JavaScript to create a dynamic application.

Here's my promise: You will actually feel like you understand what you're doing with JavaScript.

Until next time!

JavaScript Full Stack Developer currently working with fullstack JS using React and Express. Nathan loves to write about his experience in programming to help other people.

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JS Arithmetic Operators

  • Addition(+) Arithmetic Operator in JavaScript
  • Subtraction(-) Arithmetic Operator in JavaScript
  • Multiplication(*) Arithmetic Operator in JavaScript
  • Division(/) Arithmetic Operator in JavaScript
  • Modulus(%) Arithmetic Operator in JavaScript
  • Exponentiation(**) Arithmetic Operator in JavaScript
  • Increment(+ +) Arithmetic Operator in JavaScript
  • Decrement(--) Arithmetic Operator in JavaScript
  • JavaScript Arithmetic Unary Plus(+) Operator
  • JavaScript Arithmetic Unary Negation(-) Operator

JS Assignment Operators

  • Addition Assignment (+=) Operator in Javascript
  • Subtraction Assignment( -=) Operator in Javascript
  • Multiplication Assignment(*=) Operator in JavaScript
  • Division Assignment(/=) Operator in JavaScript
  • JavaScript Remainder Assignment(%=) Operator
  • Exponentiation Assignment(**=) Operator in JavaScript
  • Left Shift Assignment (<<=) Operator in JavaScript

Right Shift Assignment(>>=) Operator in JavaScript

  • Bitwise AND Assignment (&=) Operator in JavaScript
  • Bitwise OR Assignment (|=) Operator in JavaScript
  • Bitwise XOR Assignment (^=) Operator in JavaScript
  • JavaScript Logical AND assignment (&&=) Operator
  • JavaScript Logical OR assignment (||=) Operator
  • Nullish Coalescing Assignment (??=) Operator in JavaScript

JS Comparison Operators

  • Equality(==) Comparison Operator in JavaScript
  • Inequality(!=) Comparison Operator in JavaScript
  • Strict Equality(===) Comparison Operator in JavaScript
  • Strict Inequality(!==) Comparison Operator in JavaScript
  • Greater than(>) Comparison Operator in JavaScript
  • Greater Than or Equal(>=) Comparison Operator in JavaScript
  • Less Than or Equal(

JS Logical Operators

  • NOT(!) Logical Operator inJavaScript
  • AND(&&) Logical Operator in JavaScript
  • OR(||) Logical Operator in JavaScript

JS Bitwise Operators

  • AND(&) Bitwise Operator in JavaScript
  • OR(|) Bitwise Operator in JavaScript
  • XOR(^) Bitwise Operator in JavaScript
  • NOT(~) Bitwise Operator in JavaScript
  • Left Shift (
  • Right Shift (>>) Bitwise Operator in JavaScript
  • Zero Fill Right Shift (>>>) Bitwise Operator in JavaScript

JS Unary Operators

  • JavaScript typeof Operator
  • JavaScript delete Operator

JS Relational Operators

  • JavaScript in Operator
  • JavaScript Instanceof Operator

JS Other Operators

  • JavaScript String Operators
  • JavaScript yield Operator
  • JavaScript Pipeline Operator
  • JavaScript Grouping Operator

The Right Shift Assignment Operator is represented by “>>=”. This operator shifts the first operand to the right and assigns the result to the variable. It can also be explained as shifting the first operand to the right in a specified amount of bits which is the second operand integer and then assigning the result to the first operand. 

Where –

  • a is the first operand, and
  • b is the second operand.

Example 1: In this example, we will see the implementation of the right shift assignment.

   

Example 2: In this example, we will see assigning the right shift operator to the variable.

 

We have a complete list of Javascript Assignment Operators, Please check this article Javascript Assignment Operator .

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The assignment operator in JavaScript

I have this simple code on the JavaScript.

var a = 10; var b = 20; a=a+b-(b=a); document.write("a = " + a + "</br> b = " + b);

Can somebody explain me, how did these variables change the values and how is the assignment operator works in this case ? I think, that on the first step the variable b is rewrote by number from a: (b=a).

Cœur's user avatar

  • 1 What specifically are you asking about? Have you looked up how assignment operators work? Is JS your first language, or do you have knowledge of other languages? –  Carcigenicate Commented Aug 22, 2017 at 21:55
  • Assignment operator returns the assigned value, so b=a returns 10 . –  Ram Commented Aug 22, 2017 at 22:00
  • a is getting assigned the value of a + b minus the new value of b that was just assigned the value of a... I think that answer is equally as clear as the question ;) –  TinMonkey Commented Aug 22, 2017 at 22:02
  • I believe MDN's page on Operator Precedence contains all the information needed to figure this one out: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… –  shabs Commented Aug 22, 2017 at 22:05
  • @shabs The parenthesis make the precedence clear already. What the page doesn't mention is evaluation order. –  Bergi Commented Aug 22, 2017 at 22:10

3 Answers 3

It's evaluated outside-in, from left to right, as usually. The assignment expression returns the assigned value.

Ivan's user avatar

  • a=10+20-(b= a); // a=10 b=20 a= 30 - (b= a); // a=10 b=20 I thought that the first expression will be evaluated in brackets, but in this example, the first step is 10+20 . –  Alexander Commented Aug 22, 2017 at 22:16
  • @Alexander Yes, that was exactly your misconception. If (b=a) would have been evaluated before a+b , you wouldn't get the result you're actually getting. –  Bergi Commented Aug 22, 2017 at 22:27
  • @Alexander The first expression that is evaluated is the outer assignment, which then has to evaluate the - operation, which then has to evaluate its left operand (the sum) and after that its right operand (the inner assignment). Outside-in, left-to-right. –  Bergi Commented Aug 22, 2017 at 22:29

Simple explanations below.

1 . We are assigning our initial values:

2 . Here we're saying a is equal to 10+20 - (10) . Therefore a is now equal to 20 and b is equal to 10 as it was assigned to be a before we assigned a 's new value.

3 . Result:

var a = 10; var b = 20; a = a + b - (b = a); console.log("a = " + a); // a = 20 console.log("b = " + b); // b = 10

Christopher Messer's user avatar

Well, let's look closely at this: a = a + b - (b = a);

Let's replace variables with values a = (10 + 20) - (10)

This is because B == 20 until redefined at the end of the expression.

SkiZer0's user avatar

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assignment operator js

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    Have you looked up how assignment operators work? Is JS your first language, or do you have knowledge of other languages? - Carcigenicate. Commented Aug 22, 2017 at 21:55. Assignment operator returns the assigned value, so b=a returns 10. - Ram. Commented Aug 22, 2017 at 22:00.