PHP Date Exercises : Check whether the given dates are valid or not

PHP date: Exercise-10 with Solution

Write a PHP script to check whether the given dates are valid or not?

Sample Solution:

PHP Code:

var_dump(checkdate(2, 30, 2008));
var_dump(checkdate(2, 29, 2008));

Sample Output:


Flowchart :

Flowchart: Check whether a given dates is valid or not

PHP Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a PHP script to print like : Saturday the 7th
Next: Write a PHP script to get time difference in days and years, months, days, hours, minutes, seconds between two dates.

What is the difficulty level of this exercise?

PHP: Tips of the Day

PHP represents "no value" with the null keyword. It's somewhat similar to the null pointer in C-language and to the NULL value in SQL.

Setting the variable to null:


$nullvar = null; // directly
function doSomething() {} // this function does not return anything
$nullvar = doSomething(); // so the null is assigned to $nullvar

Checking if the variable was set to null:

if (is_null($nullvar)) { /* variable is null */ }
if ($nullvar === null) { /* variable is null */ }

Null vs undefined variable

If the variable was not defined or was unset then any tests against the null will be successful but they will also generate a Notice: Undefined variable: nullvar:

$nullvar = null;
if ($nullvar === null) { /* true but also a Notice is printed */ }
if (is_null($nullvar)) { /* true but also a Notice is printed */ }

Therefore undefined values must be checked with isset:

if (!isset($nullvar)) { /* variable is null or is not even defined */ }