JavaScript Assignment Operators

Assignment operators are used to assign values to variables in JavaScript.

// Lets take some variables
x = 10
y = 20

x = y // Here, x is equal to 20

console.log(x);
console.log(y);

20
20

More Assignment Operators

There are so many assignment operators as shown in the table with the description.

Addition Assignment Operator(+=)

The Addition assignment operator adds the value to the right operand to a variable and assigns the result to the variable. Addition or concatenation is possible. In case of concatenation then we use the string as an operand.

Example:

let a = 2;
const b = 3;

// Expected output: 2
console.log(a);

// Expected output: 4
console.log(a = b + 1);

2
4

Subtraction Assignment Operator(-=)

The Substraction Assignment Operator subtracts the value of the right operand from a variable and assigns the result to the variable.

Example:

let yoo = 4;

// Expected output 3
console.log(foo = yoo - 1); 

3

Multiplication Assignment Operator(*=)

The Multiplication Assignment operator multiplies a variable by the value of the right operand and assigns the result to the variable.

Example:

let yoo = 4;

// Expected output 3
console.log(foo = yoo - 1); 

3

Division Assignment Operator(/=)

The Division Assignment operator divides a variable by the value of the right operand and assigns the result to the variable.

Example:

let yoo = 10;
const moo = 2;

// Expected output 5
console.log(yoo = yoo / moo);

// Expected output Infinity    
console.log(yoo /= 0);

5
Infinity

Remainder Assignment Operator(%=)

The Remainder Assignment Operator divides a variable by the value of the right operand and assigns the remainder to the variable.

Example:

let yoo = 50;

// Expected output 0
console.log(yoo %= 10);

0

Exponentiation Assignment Operator

The Exponentiation Assignment Operator raises the value of a variable to the power of the right operand.

Example:

let yoo = 50;

// Expected output 0
console.log(yoo %= 10);

0

Left Shift Assignment Operator(<<=)

This Left Shift Assignment Operator moves the specified amount of bits to the left and assigns the result to the variable.

Example:

let yoo = 5;

// Expected output 20(In Binary 10100)
console.log(yoo <<= 2);

20

Right Shift Assignment Operator(>>=)

The Right Shift Assignment Operator moves the specified amount of bits to the right and assigns the result to the variable.

Example:

let yoo = 5;

// Expected Output 1(In binary 001)
console.log(yoo >>= 2); 

1

Bitwise AND Assignment Operator(&=)

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.

Example:

let yoo = 5;

// Expected output 0(In binary 000)
console.log(yoo &= 2);

0

Btwise OR Assignment Operator(|=)

The Btwise OR Assignment Operator uses the binary representation of both operands, does a bitwise OR operation on them, and assigns the result to the variable.

Example:

let yoo=5;
    
// Expected output 7(In binary 111)
console.log(yoo|=2);

7

Bitwise XOR Assignment Operator(^=)

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.

Example:

let yoo = 5;

// Expected output 7(In binary 111)
console.log(yoo ^= 2);

7

Logical AND Assignment Operator(&&=)

The Logical AND Assignment assigns the value of y into x only if x is a truthy value.

Example:

let name = {
    firstName: "Ram",
    lastName: "",
};

console.log(name.firstName);

// Changing the value using logical 
// AND assignment operator 
name.firstName &&= "Shyam";

// Here the value changed because 
// name.firstName is truthy 
console.log(name.firstName);

console.log(name.lastName);

// Changing the value using logical 
// AND assignment operator 
name.lastName &&= "Kumar";

// Here the value remains unchanged 
// because name.lastName is falsy 
console.log(name.lastName); 

Ram
Shyam

Logical OR Assignment Operator(||=)

The Logical OR Assignment Operator is used to assign the value of y to x if the value of x is falsy.

Example:

let name = {
    firstName: "Ram",
    lastName: "",
};

console.log(name.firstName);

// Changing the value using logical 
// OR assignment operator 
name.firstName ||= "Shyam";

// But value does not change because 
// name.firstName is truthy 
console.log(name.firstName);

console.log(name.lastName);

// Changing the value using logical 
// OR assignment operator 
name.lastName ||= "Kumar";

// The value changes because name.lastName is falsy 
console.log(name.lastName); 

Ram
Ram

Kumar

Nullish coalescing Assignment Operator(??=)

The Nullish coalescing Assignment Operator assigns the value of y to x if the value of x is null.

Example:

let x = 12;
let y = null;

let z = 13;

// The value of x will become 
// unchanged because x is not nullish. 
x ??= z;

// The value of y will be 
// changed because y is nullish. 
y ??= z;

console.log(x) // 12 
console.log(y) // 13

12
13

Supported Browsers: The browsers supported by all JavaScript Assignment operators are listed below:

• Google Chrome
• Firefox
• Opera
• Safari
• Microsoft Edge

JavaScript Assignment Operators – FAQs

What are assignment operators in JavaScript?

Assignment operators in JavaScript are used to assign values to variables. The most common assignment operator is the equals sign (=), but there are several other assignment operators that perform an operation and assign the result to a variable in a single step.

What is the basic assignment operator?

The basic assignment operator is =. It assigns the value on the right to the variable on the left.

What are compound assignment operators?

Compound assignment operators combine a basic arithmetic or bitwise operation with assignment. For example, += combines addition and assignment.

What does the += operator do?

The += operator adds the value on the right to the variable on the left and then assigns the result to the variable.

How does the *= operator work?

The *= operator multiplies the variable by the value on the right and assigns the result to the variable.

Can you use assignment operators with strings?

Yes, you can use the += operator to concatenate strings.

What is the difference between = and ==?

The = operator is the assignment operator, used to assign a value to a variable. The == operator is the equality operator, used to compare two values for equality, performing type conversion if necessary.

What does the **= operator do?

The **= operator performs exponentiation (raising to a power) and assigns the result to the variable.

S

shivani_21

Follow

Improve