checkdate can determine whether an output date is valid.
In actual work, we often need to detect data validation commonly used for user submission forms.
For example: Verify whether the time entered by the user is correct.
The syntax format of the function is as follows:
bool checkdate (int $month, int $day, int $year)
In the following example, we You can use a code to conduct experiments and write a real example. Try to see if there is February 29, 2011.
Return true if it is a valid time, return false if it is not a valid time.
<?php var_dump(checkdate(12, 31, 2018)); var_dump(checkdate(2, 29, 2011)); ?>
Output result:
bool(true)
bool(false)