array_filter function in php
Suppose we have an array $a like this
Array (  => abc  => dcf  =>  =>  =>  => )
Here we need to check whether the array element is empty and pop that element.
We can easily achieve this by array_filter()
The output will be
Array (  => abc  => dcf )
We can also write call back functions that can be passed as a parameter to array_filter() function.