JS Assignment Operator

JavaScript

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In this tutorial we will learn about JavaScript assignment operators.

We use the assignment operator to assign value to a variable.

In JavaScript (and in other programming languages) the equal to sign = is the assignment operator and it assign the value on the right side to the variable on the left side.

In the following example we are assigning the value 10 to the variable x using the assignment operator.

var x = 10;

Shorthand notation

We can combine the assignment operator and arithmetic operator together to get a shorthand notation if we are operating on a given variable.

In the following example we are adding 10 to variable x and then assigning the result to the variable x.

var x = 10;

//adding 10
x = x + 10;

console.log(x);		//this will print 20

We can get the same result by combining the operators together.

var x = 10;

//adding 10
x += 10;

console.log(x);		//this will print 20

Following is the list of shorthand assignment operators used with arithmetic operators.

Operator Symbol Example
Addition and assignment += x += 10
Subtraction and assignment -= x -= 10
Multiplication and assignment *= x *= 10
Division and assignment /= x /= 10
Modulus (to get remainder) and assignment %= x %= 10

Addition and assignment

In the following example we are assigning the result of addition to a variable.

var x = 10;
var y = 20;

//long
x = x + y

console.log(x);	//this will print 30

Shorthand

var x = 10;
var y = 20;

//shorthand
x += y

console.log(x);	//this will print 30

Subtraction and assignment

In the following example we are assigning the result of subtraction to a variable.

var x = 10;
var y = 20;

//long
x = x - y

console.log(x);	//this will print -10

Shorthand

var x = 10;
var y = 20;

//shorthand
x -= y

console.log(x);	//this will print -10

Division and assignment

In the following example we are assigning the result of division to a variable.

var x = 4;
var y = 2;

//long
x = x / y

console.log(x);	//this will print 2

Shorthand

var x = 4;
var y = 2;

//shorthand
x /= y

console.log(x);	//this will print 2

Multiplication and assignment

In the following example we are assigning the result of multiplication to a variable.

var x = 4;
var y = 2;

//long
x = x * y

console.log(x);	//this will print 8

Shorthand

var x = 4;
var y = 2;

//shorthand
x *= y

console.log(x);	//this will print 8

Modulus and assignment

In the following example we are assigning the result of modulus to a variable.

var x = 5;
var y = 2;

//long
x = x % y

console.log(x);	//this will print 1

Shorthand

var x = 5;
var y = 2;

//shorthand
x %= y

console.log(x);	//this will print 1