5.6.3 Filtering your array through a function: array_filter()This is NOT the latest copy of this book; click here for the latest version.
array array_filter ( array input [, callback function])
The final array function in this group is array_filter(), which is a very powerful function that allows you to filter elements through a function you specify. If the function returns true, the item makes it into the array that is returned, otherwise it is not. Consider this script:
<?php
function endswithy($value) {
return (substr($value, -1) == 'y');
}
$people = array("Johnny", "Timmy", "Bobby", "Sam", "Tammy", "Danny", "Joe");
$withy = array_filter($people, "endswithy");
var_dump($withy);
?>
In this script we have an array of people, most of which have a name ending with "y". However, several do not, and for one reason or another we want to have a list of people whose names ends in "y", so array_filter() is used. The function endswithy() will return true if the last letter of each array value ends with a y, otherwise false. By passing that as the second parameter to array_filter(), it will be called once for every array element, passing in the value of the element as the parameter to endswithy(), where it is checked for a "y" at the end.
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