Difference Between && and || Operators in javaScript

Last Updated : 12 Jul, 2024

In JavaScript , logical operators && (AND) and || (OR) are used to perform the logical operations on values. These operators are commonly used in the control flow and decision-making within the programs. Understanding the differences between these operators is essential for writing efficient and accurate code.

These are the following topics that we are going to discuss:

Table of Content

What is &&?

The && operator also known as the logical AND operator evaluates expressions from the left to right and returns the first falsy value encountered. If all values are truthy it returns the last value.

Returns true if both the operands are true.
Stops evaluation as the soon as it finds a falsy value.

Syntax:

condition1 && condition2

Example: This example shows the use of && operator.

JavaScript

let a = true;
let b = false;
console.log(a && b);
let c = 5;
let d = 10;
console.log(c < d && d > 0);

Output

false
true

What is ||?

The || operator also known as the logical OR operator evaluates expressions from the left to right and returns the first truthy value encountered. If all values are falsy it returns the last value.

Returns true if at least one operand is true.
Stops evaluation as the soon as it finds a truthy value.

Syntax:

condition1 || condition2

Example: This example shows the use of || operator.

JavaScript

let a = true;
let b = false;
console.log(a || b); 
let c = 0;
let d = 10;
console.log(c || d);

Output

true
10