3v4l.org

run code in 300+ PHP versions simultaneously
<?php $source = ["a" => 1, "b" => 2, "c" => 3]; $input = ["d" => 4, "b" => 10]; echo "With + operator:\n"; echo "input + source | " . json_encode($input + $source) . PHP_EOL; echo "source + input | " . json_encode($source + $input) . PHP_EOL; echo "source + input + source | " . json_encode($source + ($input + $source)) . PHP_EOL; echo "With array_merge:\n"; echo "input + source | " . json_encode(array_merge($input, $source)) . PHP_EOL; echo "source + input | " . json_encode(array_merge($source, $input)) . PHP_EOL;

preferences:
25.88 ms | 405 KiB | 5 Q