JavaScript Operators

JavaScript Operators

In this tutorial, you will learn about different operators available in JavaScript and how to use them with the help of examples.

What is an Operator?

In JavaScript, an operator is a special symbol used to perform operations on operands (values and variables). For example,

2 + 3; // 5

Here + is an operator that performs addition, and 2 and 3 are operands.


JavaScript Operator Types

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

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

JavaScript Assignment Operators

Assignment operators are used to assign values to variables. For example,

let x = 5;

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

Here's a list of commonly used assignment operators:

Operator Name Example
= Assignment operator a = 7; // 7
+= Addition assignment a += 5; // a = a + 5
-= Subtraction Assignment a -= 2; // a = a - 2
*= Multiplication Assignment a *= 3; // a = a * 3
/= Division Assignment a /= 2; // a = a / 5
%= Remainder Assignment a %= 2; // a = a % 2
**= Exponentiation Assignment a **= 2; // a = a^2

Note: The commonly used assignment operator is =. You will understand other assignment operators such as +=, -=, *= etc. once we learn arithmetic operators.


JavaScript Arithmetic Operators

Arithmetic operators are used to perform arithmetic calculations. For example,

let number = 3 + 5; // 8

Here, the + operator is used to add two operands.

Operator Name Example
+ Addition x + y
- Subtraction x - y
* Multiplication x * y
/ Division x / y
% Remainder x % y
++ Increment (increments by 1) ++x or x++
-- Decrement (decrements by 1) --x or x--
** Exponentiation (Power) x ** y

Example 1: Arithmetic operators in JavaScript

let x = 5;
let y = 3;

// addition
console.log('x + y = ', x + y);

// subtraction
console.log('x - y = ', x - y);

// multiplication
console.log('x * y = ', x * y);

// division
console.log('x / y = ', x / y);

// remainder
console.log('x % y = ', x % y);

// increment
console.log('++x = ', ++x); // x is now 6
console.log('x++ = ', x++); // x returns 6 and then increases by 1
console.log('x = ', x);

// decrement
console.log('--x = ', --x); // x is now 6
console.log('x-- = ', x--); // x returns 6 and then increases by 1
console.log('x = ', x);

//exponentiation
console.log('x ** y =', x ** y);

Visit ++ and -- operator to learn more.

Output

x + y =  8
x - y =  2
x * y =  15
x / y = 1.6666666666666667
x % y = 2
++x =  6
x++ = 6
x = 7
--x = 6
x-- = 6
x = 5
x ** y = 125

Note: The ** operator was introduced in EcmaScript 2016. And, some browsers may not support the exponentiation operator. To learn more, visit JavaScript exponentiation browser support.


JavaScript Comparison Operators

Comparison operators compare two values and return a boolean value, either true or false. For example,

let a = 3, b = 2;
console.log(a > b); // true 

Here, the comparison operator > is used to compare whether a is greater than b.

Operator Description Example
== Equal to: returns true if the operands are equal x == y
!= Not equal to: returns true if the operands are not equal x != y
=== Strict equal to: true if the operands are equal and of the same type x === y
!== Strict not equal to: true if the operands are equal but of different type or not equal at all x !== y
> Greater than: true if left operand is greater than the right operand x > y
>= Greater than or equal to: true if left operand is greater than or equal to the right operand x >= y
< Less than: true if the left operand is less than the right operand x < y
<= Less than or equal to: true if the left operand is less than or equal to the right operand x <= y

Example 2: Comparison operators in JavaScript

// equal operator
console.log(2 == 2); // true
console.log(2 == '2'); // true

// not equal operator
console.log(3 != 2); // true
console.log('hello' != 'Hello'); // true

// strict equal operator
console.log(2 === 2); // true
console.log(2 === '2'); // false

// strict not equal operator
console.log(2 !== 2'); // false
console.log(2 !== '2'); // true

Output

true
true
true
true
true
false
false
true

Comparison operators are used in decision making and loops. You will learn about the use of comparison operators in detail in the later tutorials.


JavaScript Logical Operators

Logical operators perform logical operations and return a boolean value, either true or false. For example,

let x = 5, y = 3;
(x < 6) && (y < 5); // true

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

Operator Description Example
&& Logical AND: true if both the operands are true, else returns false x && y
|| Logical OR: true if either of the operands is true; returns false if both are false x || y
! Logical NOT: true if the operand is false and vice-versa. !x

Example 3: Logical Operators in JavaScript

// logical AND
console.log(true && true); // true
console.log(true && false); // false

// logical OR
console.log(true || false); // true

// logical NOT
console.log(!true); // false

Output

true
false
true
false

Logical operators are used in decision making and loops. You will learn about the use of logical operators in detail in the later tutorials.


JavaScript Bitwise Operators


Bitwise operators perform operations on binary representations of numbers.

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

Bitwise operators are rarely used in everyday programming. If you are interested, visit JavaScript Bitwise Operators to learn more.


JavaScript String Operators

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

Example 4: String operators in JavaScript

// concatenation operator
console.log('hello' + 'world');

let a = 'JavaScript';

a += ' tutorial';  // a = a + ' tutorial';
console.log(a);

Output

helloworld
JavaScript tutorial

Note: When + is used with strings, it performs concatenation. However, when + is used with numbers, it performs addition.


Other JavaScript Operators

For the sake of completeness, here's a list of other operators available in JavaScript. You will learn about these operators in the later tutorials.

Operator Description Example
, evaluates multiple operands and returns the value of the last operand. let a = (1, 3 , 4); // 4
?: returns value based on the condition (5 > 3) ? 'success' : 'error'; // "success"
delete deletes an object's property, or an element of an array delete x
typeof returns a string indicating the data type typeof 3; // "number"
void discards the expression's return value void(x)
in returns true if the specified property is in the object prop in object
instanceof returns true if the specified object is of of the specified object type object instanceof object_type