- Prerequisite:
- JavaScript | getDate()
- JavaScript | setDate()
Problem Statement:
In order to calculate yesterday’s date in JavaScript, we need to familiarize ourselves with 2 functions.
It is an inbuilt JavaScript function that returns the day of the month as a number (1-31).
Syntax:
dateObj.getDate()
It is an inbuilt JavaScript function used to set the day of the month into a date object.
Syntax:
dateObj.setDate()
Solution:
JavaScript allows us to create a platform independent date instance that represents a single moment in time using Date constructor. An empty Date constructor creates a new date object that represents the current date and time. The Date constructor can also be specified to create a date object that represents a particular date and time. We use getDate() function to fetch the current date from the date object and subtract one day from it using the setDate() function which sets yesterday’s date onto the date object.
Example 1:
Here we will get the yesterday date, in this example we will show the output compare to today’s date.
Syntax:
var dateObj = new Date(); // empty Date constructor representing current time dateobj; // Current Time => Wed Jun 12 2019 20:52:24 GMT+0530 (India Standard Time)
The following programs illustrate the solution
Code:
<script> // JavaScript program to illustrate // calculation of yesterday's date // create a date object using Date constructor var dateObj = new Date(); // subtract one day from current time dateObj.setDate(dateObj.getDate() - 1); alert(dateObj); </script> |
Output:
// Returns Yesterday's date and time
Example 2:
Here we will get the yesterday date of pre-defined date which is Fri May 10 2019 16:30:00 GMT+0530 (India Standard Time).
Syntax:
var dateObj = new Date(2019, 04, 10, 16, 30, 00); // specified Date constructor representing particular time dateObj; // Specific Time => Fri May 10 2019 16:30:00 GMT+0530 (India Standard Time)
Code:
<script> // JavaScript program to illustrate // calculation of yesterday's date // of a specified date // create a specified date object using Date constructor var dateObj = new Date(2019, 04, 10, 16, 30, 00); // subtract one day from specified time dateObj.setDate(dateObj.getDate() - 1); alert(dateObj); </script> |
Output:
- Supported browser:
- Google Chrome
- Mozila Firefox
- Internet Explore
- Safari
- Opera