JavaScript Operators

JavaScript operators are symbols that used to perform operations on operands, like in expression ‘8 + 2 = 10’, here 8 and 2 are operands and ‘+’ is operator.

Types of operators in JavaScript:
  • Assignment Operators
  • Arithmetic Operators
  • Comparison Operators
  • Logical Operators
  • Conditional (or ternary) Operators

Let’s discuss all the above operators one by one

Assignment Operators

Below are the list of assignment operators in JavaScript:

Operator Description Example
= Assign 20+20 = 40
+= Add and assign var x=10; x+=20; Now x = 30
-= Subtract and assign var x=20; x-=10; Now x = 10
*= Multiply and assign var x=10; x*=20; Now x = 200
/= Divide and assign var x=10; x/=2; Now x = 5
%= Modulus and assign var x=10; x%=2; Now x = 0

Example:

<html>
<body>
<script>
var x = 8, y = 12;
document.write(“Value of x is “+x);
document.write(“<br/>Value of y is “+y);
x = y;
document.write(“<br/><br/>Result after x = y : “);
document.write(“<br/>Value of x is “+x);
document.write(“<br/>Value of y is “+y);

x += 1;
document.write(“<br/><br/>Result after x += 1 :”);
document.write(“<br/>Value of x is “+x);

x -= 1;
document.write(“<br/><br/>Result after x -= 1 :”);
document.write(“<br/>Value of x is “+x);

x *= 5;
document.write(“<br/><br/>Result after x *= 5 :”);
document.write(“<br/>Value of x is “+x);

x /= 5;
document.write(“<br/><br/>Result after x /= 5 :”);
document.write(“<br/>Value of x is “+x);

x %= 2;
document.write(“<br/><br/>Result after x %= 2 :”);
document.write(“<br/>Value of x is “+x);
</script>
</body>
</html>

Output:


Arithmetic Operators

Arithmetic operators are used to perform arithmetic operations on the operands.

Below are the list of arithmetic operators in JavaScript:

Operator Description Example
+ Addition 10+30 = 40
Subtraction 30-10 = 20
* Multiplication 10*10 = 100
/ Division 20/10 = 2
% Modulus (Remainder) 30%15 = 0
++ Increment var x=10; x++; Now x = 11
−− Decrement var x=10; x−−; Now x = 9

Let’s see working of Arithmetic operators with the help of example:

Example:

<html>
<body>
<script type=”text/javascript”>
var a = 12;
var b = 4;
var txt1 = “Good”;
var txt2 = “Day”;

var nextLine = “<br/>”;
document.write(“a + b = “);
result = a + b;
document.write(result);
document.write(nextLine);

document.write(“txt1 + txt2 = “);
result = txt1 + txt2;
document.write(result);
document.write(nextLine);

document.write(“a – b = “);
result = a – b;
document.write(result);
document.write(nextLine);

document.write(“a / b = “);
result = a / b;
document.write(result);
document.write(nextLine);

document.write(“a % b = “);
result = a % b;
document.write(result);
document.write(nextLine);

document.write(“a + b + txt1 = “);
result = a + b + txt1;
document.write(result);
document.write(nextLine);

a = ++a;
document.write(“++a = “);
result = ++a;
document.write(result);
document.write(nextLine);

b = −−b;
document.write(“−−b = “);
result = −−b;
document.write(result);
document.write(nextLine);

</script>
</body>
</html>

Output:


Comparison Operators

Comparison operators are used to compares the 2 operands.

Below are the list of comparison operators in JavaScript:

Operator Description Example
== Is equal to 15==30 = false
=== Identical (equal and of same type) 5==15 = false
!= Not equal to 10!=20 = true
!== Not Identical 40!==40 = false
> Greater than 20>10 = true
>= Greater than or equal to 20>=10 = true
< Less than 20<10 = false
<= Less than or equal to 20<=10 = false

Example:

<html>
<body>
<script>
var x = 15;
var y = 30;
var nextLine = “<br/>”;

document.write(“Result of (x == y) : “);
result = (x == y);
document.write(result);
document.write(nextLine);

document.write(“Result of (x < y) : “);
result = (x < y);
document.write(result);
document.write(nextLine);

document.write(“Result of (x > y) : “);
result = (x > y);
document.write(result);
document.write(nextLine);

document.write(“Result of (x != y) : “);
result = (x != y);
document.write(result);
document.write(nextLine);

document.write(“Result of (x >= y) : “);
result = (x >= y);
document.write(result);
document.write(nextLine);

document.write(“Result of (x <= y) : “);
result = (x <= y);
document.write(result);
document.write(nextLine);
</script>
</body>
</html>

Output:


Logical Operators

JavaScript support the below logical operators:

Operator Description Example
&& Logical AND (20==30 && 30==33) = false
|| Logical OR (20==30 || 22==30) = false
! Logical Not !(30==25) = true

Example:

<html>
<body>
<script>
var x = true;
var y = false;
var nextLine = “<br />”;
document.write(“Result of (x && y) : “);
result = (x && y);
document.write(result);
document.write(nextLine);
document.write(“Result of (x || y) : “);
result = (x || y);
document.write(result);
document.write(nextLine);
document.write(“Result of !(x && y) : “);
result = (!(x && y));
document.write(result);
document.write(nextLine);
</script>
</body>
</html>

Output:


Other Miscellaneous Operator of JavaScript:

Operator Description
(?:) This operator is call conditional operator and it returns value based on the condition. It is like if-else.
, Comma Operator allows multiple expressions to be evaluated as single statement.
delete It deletes a property from the object.
in In Operator checks if object has the given property
instanceof checks if the object is an instance of given type
typeof checks the type of object.
void it discards the expression’s return value.

Example of Conditional Operator (?):

<html>
<body>
<script>
var x = 5;
var y = 10;
document.write (‘Result of ((x > y) ? x is greater then y : y is greater then x) : ‘);
result = (x > y) ? ‘x is greater then y’ : ‘y is greater then x’;
document.write(‘<br/>’+result);
</script>
</body>
</html>

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