<?php
function add( $a, $b ) {
return $a + $b;
}
function mul( $a, $b ) {
return $a * $b;
}
$opers = ['mul','add'];
foreach ($opers as $oper) {
echo $oper .': '. ($oper)(3, 7) . PHP_EOL;
}
PD9waHAKCiBmdW5jdGlvbiBhZGQoICRhLCAkYiApIHsKIAlyZXR1cm4gJGEgKyAkYjsKIH0KIAogZnVuY3Rpb24gbXVsKCAkYSwgJGIgKSB7CiAJcmV0dXJuICRhICogJGI7CiB9CiAKICRvcGVycyA9IFsnbXVsJywnYWRkJ107CgogZm9yZWFjaCAoJG9wZXJzIGFzICRvcGVyKSB7CiAJZWNobyAkb3BlciAuJzogJy4gKCRvcGVyKSgzLCA3KSAuIFBIUF9FT0w7CiB9CiAKIA==