- str_repeat: documentation ( source)
- memory_get_usage: documentation ( source)
- printf: documentation ( source)
<?php
$mem = memory_get_usage();
$a = str_repeat('A',1048576);
$mema = memory_get_usage() - $mem;
$b = 1 ? $a : 0;
$memb = memory_get_usage() - $mem;
printf( '%1.1f', $memb / $mema );