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run code in 300+ PHP versions simultaneously
<?php class SingleInstance { private static $instances = []; public static function load($class, $args = null) { $checksum = md5($class.implode(', ', $args)); if (array_key_exists($checksum, self::$instances)) { echo "Hit!"; return self::$instances[$checksum]; } self::$instances[$checksum] = new $class(... $args); return self::$instances[$checksum]; } } class Words { private $word; private $word2; public function __construct($word, $word2) { $this->word = $word; $this->word2 = $word2; } public function show() { return $this->word." ".$this->word2; } } $a = SingleInstance::load('Words', ['Dog', 'Word1']); echo $a->show().PHP_EOL; $b = SingleInstance::load('Words', ['Cat', 'Word2']); echo $b->show().PHP_EOL; $c = SingleInstance::load('Words', ['Cat', 'Word2']); echo $c->show().PHP_EOL;

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