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run code in 300+ PHP versions simultaneously
<?php $array = array('a' => false, 'b' => null, 'c' => '', 'd' => 'd'); function asBool($value) { return $value ? 'true' : 'false' ; } foreach ($array as $k => $v) { printf( '%s => %s isset = %s ake = %s' . PHP_EOL, $k, $v, asBool(isset($array[ $k ])), asBool(array_key_exists($k, $array)) ); }

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62.4 ms | 402 KiB | 5 Q