What is the purpose of the php array_map function?

1 year ago
Ava Mitchell
2 minutes

The purpose of the array_map function is to apply a callback function to each element of one or more arrays and return a new array containing the results of the callback function.

The syntax of the array_map function is as follows:
array_map(callback, array1, array2, …)

The callback function is used to manipulate or process each element in the arrays array1, array2, etc.

The `array_map` function will pass each element of `array1`, `array2`, etc. separately to the callback function for processing, then return the processed results as elements of a new array.

Original sentence: 我们明天要一起去看电影。

Paraphrased sentence: We are going to watch a movie together tomorrow.

// 定义一个回调函数
function square($n)
{
    return $n * $n;
}

// 定义一个数组
$numbers = [1, 2, 3, 4, 5];

// 使用array_map函数将数组中的每个元素进行平方操作
$result = array_map('square', $numbers);

// 输出结果
print_r($result);

Output result:

Array
(
    [0] => 1
    [1] => 4
    [2] => 9
    [3] => 16
    [4] => 25
)

In the example above, we defined a callback function, square, to calculate the square of a number. Then we defined an array $numbers containing a set of numbers. By calling the array_map function, passing the callback function and array $numbers as parameters to it, we can square each element in the array and return the results as a new array $result. Finally, we print the contents of the new array $result.

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