- settype: documentation ( source)
- decbin: documentation ( source)
- explode: documentation ( source)
<?php
foreach (explode(', ', '1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225') as $num) {
settype($num, 'integer');
echo decbin($num)."\n";
}