PHP 内存管理机制对函数性能的影响和优化

// 不优化function sumArray($arr) {    $sum = 0;    foreach ($arr as $value) {        $sum += $value;    }    return $sum;}// 优化后function sumArrayOptimized($arr) {    $sum = 0;    foreach ($arr as &amp;$value) { // 传递引用        $sum += $value;    }    return $sum;}$arr = range(1, 10000);$time1 = microtime(true);sumArray($arr);$time2 = microtime(true);$diff1 = $time2 - $time1;$time1 = microtime(true);sumArrayOptimized($arr);$time2 = microtime(true);$diff2 = $time2 - $time1;echo "不优化：$diff1 秒<br>";echo "优化后：$diff2 秒<br>";