Left Shift (<<) Bitwise Operator in JavaScript

JavaScript Left Shift Operator is used to operate on the two operands. The first operand is the number and the right operand specifies the number of bits to shift to the left. The operation is represented by the “<<” symbol. Mainly the left shift operator is used to multiply the number by any power of 2.

Let’s look at the table below to better understand the output of the Left Shift Operation.

A	6 ( 00000000000000000000000000000110 )
B	1 ( 00000000000000000000000000000001 )
OUTPUT ( A << B )	12 ( 00000000000000000000000000001100 )

Syntax:

a << 1

Example 1: In this example, we will use the left shift operator on the numbers.

Javascript

let a = 4;
console.log(a<<1);
console.log(a<<4);

Output:

8
64

Example 2: In this example, we will raise different numbers to the power two.

Javascript

function multiplyPower(a, b) {
    return a<<b;
}
console.log(multiplyPower(2,4));
console.log(multiplyPower(3,2))

Output: In the first function call, 2 is left shift by 4 which is equivalent to 2 multiplied by 2 raise to power 4 so we get 32. In the second function call, 3 is left shift by 2 which is equivalent to 3 multiplied by 2 raise to power 2 so we get 12. When we use this approach the code becomes efficient as the power operation is heavy but by using XOR it becomes shorter and easier to implement.

32
12

Supported Browsers:

• Chrome
• Edge
• Firefox
• Opera
• Safari

We have a complete list of JavaScript Bitwise Operators, to check those please go through, the JavaScript Bitwise Operators article