- substr: documentation ( source)
- time: documentation ( source)
- memory_get_usage: documentation ( source)
- md5: documentation ( source)
<?php
$str = '';
for ($i = 0; $i < 1e4; $i++) {
$str .= md5(time());
}
echo strlen($str);
$memory = memory_get_usage(true);
substr($str, 0);
echo memory_get_usage(true)-$memory;