The date.valueOf() method is used to get the number of milliseconds between 1 January 1970 00:00:00 UTC and the given date.
Syntax:
dateObj.valueOf()
Parameters: This method does not accept any parameter. It is just used along with a Date object created using Date() constructor.
Return Values: It returns the number of milliseconds between 1 January 1970 00:00:00 UTC and the given date as the contents of the Date() constructor.
Note: The DateObj is a valid Date object created using Date() constructor whose contents are used to get the number of milliseconds between 1 January 1970 00:00:00 UTC and the given date as the contents of the Date() constructor.
Below are examples of Date.valueOf() method.
Example 1:
javascript
// Here a date has been assigned// while creating Date objectlet dateobj = new Date('October 15, 1996 05:35:32');// Getting the number of milliseconds between // 1 January 1970 00:00:00// UTC and the given date as the content of // the above Date() constructor.let B = dateobj.valueOf();// Printing the calculated number// of milliseconds.console.log(B); |
Output:
845337932000
Example 2: If nothing as a parameter is passed while creating a date object but still the valueOf() method returns the number of milliseconds between 1 January 1970 00:00:00 UTC and the current date.
javascript
// Here nothing has been assigned// while creating Date objectlet dateobj = new Date();// Getting the number of milliseconds between // 1 January 1970 00:00:00// UTC and the current date.let B = dateobj.valueOf();// Printing the calculated number // of milliseconds.console.log(B); |
Output:
1524387231290
Example 3: Date of a month ranging between 1 to 31. If the date is taken as 35 which is out of the date range, it returns NaN i.e, not a number.
javascript
// Here a date has been assigned// while creating Date objectlet dateobj = new Date('October 35, 1996 05:35:32');// Getting the number of milliseconds between // 1 January 1970 00:00:00// UTC and the given date.let B = dateobj.valueOf();// Printing the calculated number // of milliseconds.console.log(B); |
Output:
NaN
Some Important Points:
- Months, Dates, hours, minutes, seconds, and milliseconds should all be in their respective range. Otherwise valueOf() method returns NaN i.e, not a number.
- The range of Months, Dates, hours, minutes, seconds, and milliseconds are 0 to 11, 1 to 31, 0 to 23, 0 to 59, 0 to 59, and 0 to 999 respectively.
We have a complete list of Javascript Date Objects, to check those please go through this Javascript Date Object Complete reference article.
Supported Browsers: The browsers supported by JavaScript Date valueOf() method are listed below:
- Google Chrome
- Internet Explorer
- Mozilla Firefox
- Opera
- Safari
We have a Cheat Sheet on Javascript where we covered all the important topics of Javascript to check those please go through Javascript Cheat Sheet-A Basic guide to JavaScript.
