- array_map: documentation ( source)
- var_dump: documentation ( source)
- implode: documentation ( source)
- array_keys: documentation ( source)
- str_split: documentation ( source)
<?php
$string = str_split('This is a string!');
$i = 0;
var_dump(implode('', array_map(function($val, $key) {
return $key % 2 ? $val : null;
}, $string, array_keys($string))));