PHP array key value flipping: Comparative performance analysis of different methods

The performance comparison of PHP array key value flipping methods shows that the array_flip() function performs better than the for loop in large arrays (more than 1 million elements) and takes less time. The for loop method of manually flipping key values ​​takes a relatively long time.

PHP Array Key Value Flip: Comparative Performance Analysis of Different Methods

Introduction

In PHP, array key value flipping is a common operation. It swaps the keys and values ​​in an array to form a new array. This article will compare the performance of different array key value flipping methods and provide practical cases.

Method comparison

array_flip() function

array_flip() The function is built-in in PHP Array key value flip function. Its syntax is very simple:

array_flip($array);

For loop

You can also use the for loop to manually flip the key values ​​​​of the array:

$newArray = [];
foreach ($array as $key => $value) {
    $newArray[$value] = $key;
}

Practical combat Case

The following is a practical case that compares the performance of the array_flip() function and the for loop method:

$array = range(1, 1000000); // 创建一个包含 100 万个元素的数组

// 使用 array_flip() 函数翻转键值
$startTime = microtime(true);
$flippedArray1 = array_flip($array);
$endTime = microtime(true);
$time1 = $endTime - $startTime;

// 使用 for 循环翻转键值
$startTime = microtime(true);
$flippedArray2 = [];
foreach ($array as $key => $value) {
    $flippedArray2[$value] = $key;
}
$endTime = microtime(true);
$time2 = $endTime - $startTime;

echo "array_flip() 函数耗时：$time1 秒<br>";
echo "for 循环耗时：$time2 秒<br>";

if ($flippedArray1 == $flippedArray2) {
    echo "两个数组相等<br>";
}

Result

In the test environment (PHP 8.2):

• ##array_flip() The function takes: 0.0021 seconds
for loop The time taken is: 0.0052 seconds

This shows that for large arrays (more than 1 million elements), the

array_flip() function performs better than the for loop.

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