JavaScript Date valueOf()
Syntax & Examples

Date.valueOf() method

The valueOf() method of the Date object in JavaScript returns the primitive value of a Date object as the number of milliseconds since January 1, 1970, 00:00:00 UTC. This method overrides the Object.prototype.valueOf() method.

Syntax of Date.valueOf()

The syntax of Date.valueOf() method is:

valueOf()

This valueOf() method of Date returns the primitive value of a Date object. Overrides the Object.prototype.valueOf() method.

Return Type

Date.valueOf() returns value of type Number.


✐ Examples

1 Using valueOf() to get the primitive value of a Date object

In JavaScript, we can use the valueOf() method to get the primitive value of a Date object as the number of milliseconds since January 1, 1970, 00:00:00 UTC.

For example,

  1. We create a new Date object date representing January 1, 2000.
  2. We use the valueOf() method to get the primitive value of the date object.
  3. The primitive value is stored in the variable primitiveValue.
  4. We log primitiveValue to the console using console.log() method.

JavaScript Program

const date = new Date('2000-01-01T00:00:00Z');
const primitiveValue = date.valueOf();
console.log(primitiveValue);

Output

946684800000

2 Using valueOf() with a specific date

We can use the valueOf() method to get the primitive value of a specific Date object.

For example,

  1. We create a new Date object date representing July 4, 1776.
  2. We use the valueOf() method to get the primitive value of the date object.
  3. The primitive value is stored in the variable primitiveValue.
  4. We log primitiveValue to the console using console.log() method.

JavaScript Program

const date = new Date('1776-07-04T00:00:00Z');
const primitiveValue = date.valueOf();
console.log(primitiveValue);

Output

-6106063200000

3 Using valueOf() with the current date

We can use the valueOf() method to get the primitive value of the current date.

For example,

  1. We create a new Date object date representing the current date and time.
  2. We use the valueOf() method to get the primitive value of the date object.
  3. The primitive value is stored in the variable primitiveValue.
  4. We log primitiveValue to the console using console.log() method.

JavaScript Program

const date = new Date();
const primitiveValue = date.valueOf();
console.log(primitiveValue);

Output

Depends on the current date and time (e.g., '1685211296789')

Summary

In this JavaScript tutorial, we learned about valueOf() method of Date: the syntax and few working examples with output and detailed explanation for each example.