This is pure PHP, without calling external functions, except for strlen.
function endsWith ($ends, $string)
{
$strLength = strlen ($string);
$endsLength = strlen ($ends);
for ($i = 0; $i < $endsLength; $i++)
{
if ($string [$strLength - $i - 1] !== $ends [$i])
return false;
}
return true;
}