php - PHP中str_replace的性能

在这里，我有2种使用str_replace替换给定短语中的字符串的方法。

// Method 1
$phrase  = "You should eat fruits, vegetables, and fiber every day.";
$healthy = array("fruits", "vegetables", "fiber");
$yummy   = array("pizza", "beer", "ice cream");
$phrase = str_replace($healthy, $yummy, $phrase);

// Method 2
$phrase  = "You should eat fruits, vegetables, and fiber every day.";
$phrase = str_replace("fruits", "pizza", $phrase);
$phrase = str_replace("vegetables", "beer", $phrase);
$phrase = str_replace("fiber", "ice cream", $phrase);

哪种方法更有效(就执行时间和使用的资源而言)？

假设实际词组更长(例如50,000个字符)，并且要替换的词有更多对。

我在想方法2会调用str_replace 3次，这将花费更多的函数调用；另一方面，方法1创建2个数组，并且str_replace需要在运行时解析2个数组。

最佳答案

我更喜欢使用方法1作为它的更清洁和更有条理的方法，方法1提供了使用其他来源的配对的机会，例如:数据库中的坏词表。方法2将需要另一个排序循环。

<?php
$time_start = microtime(true);
for($i=0;$i<=1000000;$i++){
    // Method 1
    $phrase  = "You should eat fruits, vegetables, and fiber every day.";
    $healthy = array("fruits", "vegetables", "fiber");
    $yummy   = array("pizza", "beer", "ice cream");
    $phrase = str_replace($healthy, $yummy, $phrase);
}
$time_end = microtime(true);
$time = $time_end - $time_start;
echo "Did Test 1 in ($time seconds)\n<br />";



$time_start = microtime(true);
for($i=0;$i<=1000000;$i++){
    // Method2
    $phrase  = "You should eat fruits, vegetables, and fiber every day.";
    $phrase = str_replace("fruits", "pizza", $phrase);
    $phrase = str_replace("vegetables", "beer", $phrase);
    $phrase = str_replace("fiber", "ice cream", $phrase);

}
$time_end = microtime(true);
$time = $time_end - $time_start;
echo "Did Test 2 in ($time seconds)\n";
?>

在(3.6321988105774秒)中测试了1

在(2.8234610557556秒)中测试了2

编辑:在进一步的测试字符串重复到50k时，ajreal的迭代次数和建议减少了，差异是如此之小。

<?php
$phrase  = str_repeat("You should eat fruits, vegetables, and fiber every day.",50000);
$healthy = array("fruits", "vegetables", "fiber");
$yummy   = array("pizza", "beer", "ice cream");

$time_start = microtime(true);
for($i=0;$i<=10;$i++){
    // Method 1
    $phrase = str_replace($healthy, $yummy, $phrase);
}
$time_end = microtime(true);
$time = $time_end - $time_start;
echo "Did Test 1 in ($time seconds)\n<br />";



$time_start = microtime(true);
for($i=0;$i<=10;$i++){
    // Method2
    $phrase = str_replace("fruits", "pizza", $phrase);
    $phrase = str_replace("vegetables", "beer", $phrase);
    $phrase = str_replace("fiber", "ice cream", $phrase);

}
$time_end = microtime(true);
$time = $time_end - $time_start;
echo "Did Test 2 in ($time seconds)\n";
?>

在(1.1450328826904秒)中测试了1

在(1.3119208812714秒)中进行了测试2

关于php - PHP中str_replace的性能，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/8485511/