JavaScript Number() Constructor (original) (raw)

Last Updated : 11 Jul, 2025

Javascript Number() Constructor is used to create a new number object but, if we call it as a function on another data type it will perform type conversion to number if possible.

Syntax:

Number(object)

Parameters: This function accepts a single parameter as mentioned above and described below:

Return Values: The number() constructor returns the number format for any type of javascript variable.

Below are examples of the Number() Constructor:

Example 1: In this example, we will create a new number using Number Constructor

JavaScript `

function func() { let a = new Number(5); console.log(a); } func();

`

Output:

Number {5}

Example 2: In this example, we will convert a Number String to Number using Number constructor as a function.

JavaScript `

function func() { // Original string let a = "10";

let value = Number(a);
console.log(value);

} func();

`

Output:

10

Example 3: In this example, we will convert the date into a number, and the conversion will return the converted date in milliseconds.

JavaScript `

function func() { let value = Number(new Date("2017-09-30")); console.log(value); } func();

`

Output:

1506729600000

Example 4: In this example, we will convert a Non-Number String to a Number using the Number constructor as a function.

JavaScript `

function func() { let value = Number("John"); console.log(value); } func();

`

Output: The conversion fails as no number value is detected when conversion takes place

NaN

Supported Browsers:

We have a complete list of JavaScript Number constructor, properties, and methods list, to know more about the numbers please go through that article.