Fill an array with values, specifying keys in PHP

Description

The following code shows how to fill an array with values, specifying keys.

Example

// w  w  w. j a v a2s . c o m
<?php
function test_odd($var){
   return($var & 1);
}

$a1=array("a","b",2,3,4);
print_r(array_filter($a1,"test_odd"));

?>

The code above generates the following result.