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4 PHP Tips to Improve Script Performance

Typically, I write code using obvious regular PHP functions to solve the corresponding problem. But for some of these problems I've come across some alternative solutions that specifically improved performance.

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In this article, I would like to introduce some alternatives. This is useful if you are looking for possibilities to reduce execution time in production. Let's see which PHP method might be replaced by a more performant method and whether there are any cost or trade-off issues.

1. Remove Duplicates

You have a large array containing duplicates and want to remove them so that it only has an array of unique values.

Regular

array_unique($array);

Alternative

array_keys(array_flip($array));

Performance

I created An array with over 4 million elements and 3 million duplicates. This is the best result:

Method	Execution time Processing time
array_unique	787.31 ms
array_keys array_flip	434.03 ms

The alternative method is 1.8 times (44.87%) faster in this measurement. On average, the speedup is about 1.5x (30%). Trade-off: This only works for simple 1D arrays because array_flip replaces keys with values.

2. Get random array records

You have a large array and want to select a random value from it.

Regular

array_rand($array);

Alternative

$array[mt_rand(0, count($array) - 1)];

Performance

I created An array containing 5 million elements. This is the best result:

0.95 microsecond

Method	Execution time Processing time
array_rand	25.99 microseconds
##mt_rand

The alternative is that this measurement is

27.3 times faster (96.33%). On average, the speedup is about 8x (87%). This result is particularly surprising because so is the implementation of the mt_randMersenne Twister random number generator, and since PHP 7.1 the internal randomization algorithm has been changed to use the exact same algorithm.

#3. Testing alphanumeric characters

You have a string that you want to test if it contains only alphanumeric characters.

Regular

preg_match('/^[a-zA-Z0-9]+$/', $string);

Alternative

ctype_alnum($string);

Performance

I created An array containing over 100k alphanumeric and non-alphanumeric strings. This is the best result:

MethodExecution time Processing time15.39 ms##ctype_alnum

在此测量中，替代方法快了7.5倍（86.59％）。平均而言，速度提高了约4倍（76％）。可以将相同的内容应用于ctype_alpha()（检查字母字符）和ctype_digit()（检查数字字符）。

4.替换子字符串

您有一个字符串，想要用另一个子字符串替换它的一部分。

常规

str_replace('a', 'b', $string);

替代

strtr($string, 'a', 'b');

表现

我创建了一个包含500万个随机字符串的数组。这是最佳结果：

preg_match
2.06 ms

方法	执行时间处理时间
str_replace	676.59毫秒
strtr	305.59毫秒

另一种方法是2.2倍（54.83％）在该测量更快。平均而言，速度提高了约2倍（51％）。

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其他性能改进

这是我整合到我的编码约定中的一些其他要点，发现它们可以稍微改善性能（如果适用）：

• 首选JSON比XML
• 在循环之前而不是在循环的每个迭代中声明变量
• 避免在循环头中进行函数调用（在每次迭代中均for ($i=0; $i<count($array); $i)在count()get中调用）
• 重置内存消耗变量
• 优先选择select语句而不是多个if语句
• 优先于require / include而不是require_once / include_once（确保适当的操作码缓存）

最后几句话：我知道有关过早优化的讨论。我同意生产中的性能取决于瓶颈，例如数据库查询，在处理性能时应重点关注。但是我认为，如果有更快的替代方法，例如在正则表达式更易于处理和维护的情况下，为什么不使用它们呢？

最后

我们已经看到，即使使用当前的PHP 7.4（已经比以前的PHP版本快很多），也可以通过其他方法来提高脚本性能。如果您想亲自验证本文中提供的数据，我创建了一个包含所有测试的存储库：

devmount / faster-php

测试提高 PHP 脚本性能的不同方法

我使用了Bart van Hoekelen的出色工具来衡量执行时间。

转载自：Andreas

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