Online PHP editor | output for fbFkb

<?php $classmap1 = array(); for ($i=1; $i<=10000; $i++) { $classmap1['a'.$i] = $i+1; } $classmap2 = array(); for ($i=1; $i<=10000; $i++) { $classmap2['b'.$i] = $i+1; } $startTimeMerge = microtime(true); $map = array_merge($classmap1, $classmap2); $endTimeMerge = microtime(true); $startTimeForeach = microtime(true); foreach ($classmap2 as $k => $v) { $classmap1[$k] = $v; } $endTimeForeach = microtime(true); function amerge(array $a, array $b) { foreach ($b as $key => $value) { if (array_key_exists($key, $a)) {print 111;die; if (is_int($key)) { $a[] = $value; } elseif (is_array($value) && is_array($a[$key])) { $a[$key] = static::merge($a[$key], $value); } else { $a[$key] = $value; } } else { $a[$key] = $value; } } return $a; } $startTimeFunc = microtime(true); amerge($classmap1, $classmap2); $endTimeFunc = microtime(true); echo "Merging took " . (($endTimeMerge - $startTimeMerge)*1000) ." microseconds<br />\n"; echo "Foreach took " . (($endTimeForeach - $startTimeForeach)*1000) ." microseconds<br />\n"; echo "Func took " . (($endTimeFunc - $startTimeFunc)*1000) ." microseconds<br />\n";