JavaScript Assignment Operators

The JavaScript Assignment operators are used to assign values to the declared variables. Equals (=) operator is the most commonly used assignment operator. For example:

var i = 10;

The below table displays all the 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

For this example, We are using two integer variables a, and Total, and their values are 7 and 21. We are going to use these two variables to show you the working functionality of all the Assignment Operators in JS.

<!DOCTYPE html>
<html>
<head>
    <title> JavascriptAssignmentOperators</title>
</head>
<body>
    <h1> AssignmentOperations </h1>
<script>
   var a = 7, Total = 21;

   document.write("Value of the Total = " + (Total += a) + "<br />");
   document.write("Value of the Total = " + (Total -= a) + "<br />");
   document.write("Value of the Total = " + (Total *= a) + "<br />");   
   document.write("Value of the Total = " + (Total /= a) + "<br />");
   document.write("Value of the Total = " + (Total %= a) + "<br />");
</script>
</body>
</html>
JavaScript Assignment Operators 1

In this JavaScript Assignment Operators program, We declared 2 integer values a, and Total, and we assigned values 7 and 21 respectively. Below statements will perform Assignment operations on a and Total and then write the output to the respective browser.

Let us see the functionality of the JS Assignment Operators

document.write("Value of the Total = " + (Total += a) + "<br />");

Total += a means

Total = Total + a = 21 + 7 = 28

document.write("Value of the Total = " + (Total -= a) + "<br />");

Total -= a means

Total = Total – a = 28 – 7 = 21

document.write("Value of the Total = " + (Total *= a) + "<br />");

Total *= a means

Total = Total * a = 21 * 7 = 147

document.write("Value of the Total = " + (Total /= a) + "<br />");

Total /= a means

Total = Total / a = 147 / 7 = 21

document.write("Value of the Total = " + (Total %= a) + "<br />")

Total %= a means

Total = Total + a = 21 % 7 = 0 (Remainder of 21/7 is = 0)

JavaScript Assignment Operators Example 2

For this JavaScript example, we are using two integer variables, a and Total, whose values are 7 and 21. We will use these variables to show you, How to display the Assignment Operators output in Paragraphs.

<!DOCTYPE html>
<html>
<head>
    <title> Example 2</title>
</head>
<body>
    <h1> Assignment Operations </h1>
    <p id = 'add'> Plus Equal to </p>
    <p id = 'sub'> Subtraction Equal to </p>
    <p id = 'mul'> Multiplication Equal to </p>
    <p id = 'div'> Division Equal to </p>
    <p id = 'mod'> Modulus Equal to </p>
<script>
   var a = 3, Total = 12;

   document.getElementById("add").innerHTML = "Value of the Total = " + (Total += a);
   document.getElementById("sub").innerHTML = "Value of the Total = " + (Total -= a);
   document.getElementById("mul").innerHTML = "Value of the Total = " + (Total *= a);
   document.getElementById("div").innerHTML = "Value of the Total = " + (Total /= a);
   document.getElementById("mod").innerHTML = "Value of the Total = " + (Total %= a);

</script>
</body>
</html>
Assignment Operations

Value of the Total = 15

Value of the Total = 12

Value of the Total = 36

Value of the Total = 12

Value of the Total = 0

About Suresh

Suresh is the founder of TutorialGateway and a freelance software developer. He specialized in Designing and Developing Windows and Web applications. The experience he gained in Programming and BI integration, and reporting tools translates into this blog. You can find him on Facebook or Twitter.