JavaScript | date.setDate() function

The date.setDate() is an inbuilt function in JavaScript which is used to set date of a month into a date object which are created using date() constructor.
Syntax:

dateObj.setDate(date_Value);
DateObj is a valid Date object created using Date() 
constructor in which we want to set the date of a month.

Parameter : Here parameter is date_Value 
i.e, the value of date which is used to set in date() 
constructor.
Return Values : It returns the new i.e 
updated date of the month which is set by setDate() function.
The date of the month is an integer value ranging from 1 to 31.

Output:

> 15

Errors and Exceptions

• Code #1: Here as we know that date of the month lies in between 1 to 31 but if we suppose to set date of 33, it will set date 2 for the next month because and this date 2 becomes date for next of the previous month.

  // Here a date has been assigned // while creating Date object var dateobj = new Date('October 13, 1996 05:35:32');    // new date 33 of the month is being set in above Date // Object with the help of setDate() function dateobj.setDate(33);    // new date of the month from above Date Object is // being extracted using getDate() var B = dateobj.getDate();    // new month from above Date Object is // being extracted using getMonth() var C = dateobj.getMonth();    // Printing new date of the month console.log(B);    // Printing new month console.log(C);

  Output:

  > 2
  > 10

  In above output 2 is date of the November month and 10 is the month of November because month name start from 0 to 11 i.e, 0 for January and 11 for December.

• Code #2: If in Date() constructor we do not give any date of the month, still setDate() function set new date which is given as its parameter.

  // Here date has not been assigned // while creating Date object var dateobj = new Date('October, 1996 05:35:32');    // new date 12 of the month is being set in above Date // Object with the help of setDate() function dateobj.setDate(12);    // new date of the month from above Date Object is // being extracted using getDate() var B = dateobj.getDate();    // Printing new date of the month console.log(B);

  Output:

  > 12
  

• Code #3: If nothing as parameter is given in Date() constructor, still setDate() function set date but month becomes current month.

  // Here a date has been assigned // while creating Date object var dateobj = new Date();    // new date 13 of the month is being set in above Date // Object with the help of setDate() function dateobj.setDate(13);    // date of the month from above Date Object is // being extracted using getDate() var B = dateobj.getDate();    // month from above Date Object is // being extracted using getMonth() var C = dateobj.getMonth();    // Printing new date of the month console.log(B);    // Printing new month console.log(C);

  Output:

  > 13
  > 2
  

• Code #4: If new date of the month set to zero (0), the new date will be set to the last day of the previous month.

  // Here a date has been assigned // while creating Date object var dateobj = new Date('October 13, 1996 05:35:32');    // new date 0 of the month is being set in above Date // Object with the help of setDate() function dateobj.setDate(0);    // date of the month from above Date Object is // being extracted using getDate() var B = dateobj.getDate();    // month from above Date Object is // being extracted using getMonth() var C = dateobj.getMonth();    // Printing new date of the month console.log(B);    // Printing new month console.log(C);

  Output:

  > 30
  > 8