PHP array reversal performance comparison

In PHP, the methods for reversing arrays in order of performance from fast to slow are: array_reverse() function, manual reversal using for loop, manual reversal using while loop. When the test array size is 10,000, the array_reverse() function execution time is 0.0010440111160278 milliseconds, manual reversal using a for loop is 0.0014300346374512 milliseconds, and manual reversal using a while loop is 0.0014059543609619 milliseconds.

PHP array reversal performance comparison: practical case

Introduction

Reverse Converting an array is a common programming task that involves arranging the elements in an array into the reverse order. There are several ways to achieve array reversal in PHP. This article will compare the performance of different inversion methods and provide a practical case to illustrate the results.

Method

We compare the following methods of reversing an array:

• array_reverse() Function
• Manual usefor Loop reversal
• Manual usewhile Loop reversal

Practical case

We create an array of 10,000 integers and measure the execution time for each inversion method.

Code

$array = range(1, 10000);

// array_reverse()
$start = microtime(true);
$reversed_array_array_reverse = array_reverse($array);
$end = microtime(true);
$time_array_reverse = $end - $start;

// 手动反转，使用 `for` 循环
$start = microtime(true);
$reversed_array_for = [];
for ($i = count($array) - 1; $i >= 0; $i--) {
  $reversed_array_for[] = $array[$i];
}
$end = microtime(true);
$time_for = $end - $start;

// 手动反转，使用 `while` 循环
$start = microtime(true);
$reversed_array_while = [];
while (count($array) > 0) {
  $reversed_array_while[] = array_pop($array);
}
$end = microtime(true);
$time_while = $end - $start;

// 输出结果
echo "时间：array_reverse(): " . $time_array_reverse . " 毫秒\n";
echo "时间：手动反转，使用 `for` 循环: " . $time_for . " 毫秒\n";
echo "时间：手动反转，使用 `while` 循环: " . $time_while . " 毫秒\n";

Result

In our test, the array_reverse() function Fastest execution, followed by manual reversal using a for loop, then manual reversal using a while loop. The following are the results for a tested array size of 10,000:

时间：array_reverse(): 0.0010440111160278 毫秒
时间：手动反转，使用 `for` 循环: 0.0014300346374512 毫秒
时间：手动反转，使用 `while` 循环: 0.0014059543609619 毫秒

Conclusion

For smaller arrays, the array_reverse() function is the array inverse The fastest option. However, when arrays get larger, manually reversing the loop using for may become a better option. Manual reversal using a while loop is generally slower than using a for loop.

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