v2ex.com/t/51889

gistfile1.php

<?php
	function test_void () {	return false;	}

	function test_1 ($params = array()) {

		if (is_array($params)) {

			foreach ($params as $param) {

				test_void($param);

			}

		}

	}

	function test_2 ($params = array()) {

		$params = is_array($params) ? $params : array();

		foreach ($params as $param) {

			test_void($param);

		}

	}

	function test_item ($function = 'test_void', $times = 100000) {

		$time = microtime(true);

		for ($i = 0; $i < $times; $i++) { 
			
			$function(array(time()));

		}

		for ($i = 0; $i < $times; $i++) { 
			
			$function(time());

		}

		$time = microtime(true) - $time;

		echo "{$function}: {$time}, {$times} \n";

	}

	test_item('test_1');
	test_item('test_2');