JavaScript Number.isNaN() Method

The Number.isNaN() method in JavaScript is used to determine whether the passed value is NaN (Not-a-Number) and its type is Number.

Number.isNaN() Syntax

Number.isNaN(value)

Number.isNaN() Parameters

• Value: It is the value that is to be tested for NaN. 

Number.isNaN() Return Value:

The Number.isNaN() method in JavaScript returns true if the passed value is Nan and is of the type number, else it returns false. 

JavaScript Number.isNaN() Method Examples

Example 1: Checking if a Number is NaN in JavaScript

The GFGFun() function initializes an empty string res. It then appends the result of the Number.isNaN(123) method call to res. Since 123 is a valid number, Number.isNaN() returns false.

Javascript

function GFGFun() {
    let res = "";
    res = res + Number.isNaN(123);
    console.log(res);
}
GFGFun();

Output

false

Example 2: Checking if Division by Zero Results in NaN

The GFGFun() function initializes an empty string res. It then appends the result of the expression Number.isNaN(0 / 0) to res. Since division by zero results in NaN, Number.isNaN() returns true.

Javascript

function GFGFun() {
    let res = "";
    res = res + Number.isNaN(0 / 0);
    console.log(res);
}
GFGFun();

Output

true

Example 3: Checking if a Number is NaN in JavaScript

The function GFGFun() initializes an empty string res, then appends the result of Number.isNaN(321) to res. Since 321 is a valid number, Number.isNaN() returns false.

Javascript

function GFGFun() {
    let res = "";
    res = res + Number.isNaN(321);
    console.log(res);
}
GFGFun();

Output

false

We have a complete list of Javascript Number Object methods, to check those please go through this Javascript Number Complete reference article.

Supported Browsers:

• Google Chrome 25 and above
• Firefox 15 and above
• Apple Safari 9 and above
• Opera 15 and above
• safari 9 and above