Convert php string array to int

In PHP, converting a string array to an integer array is a common operation. This article explores how to do this.

First of all, we need to clarify a concept: what is a string array? Simply put, a string array is an array of strings. As shown below:

$arr = array("1", "2", "3", "4");

This is an array containing four strings. Now we want to convert it to an array of integers, how to do it?

A simple way is to use the array_map function that comes with PHP. This function accepts a callback function and an array as parameters, applies the callback function to each array element, and returns a new array.

The sample code is as follows:

$arr = array("1", "2", "3", "4");

$newArr = array_map(function($value) {
    return intval($value);
}, $arr);

print_r($newArr);

In the above code, we set the callback function to intval(), which can convert a string into an integer. So array_map will iterate through each element in the $arr array and pass it to intval(), resulting in a new array of integers.

The output results are as follows:

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

We can see that the original string array has been successfully converted into an integer array.

In addition to array_map, PHP also provides another function array_walk, which can also accomplish the same operation. The difference is that array_walk passes the original array to the callback function by reference, so the element values ​​in the original array can be modified directly.

The sample code is as follows:

$arr = array("1", "2", "3", "4");

array_walk($arr, function(&$value) {
    $value = intval($value);
});

print_r($arr);

In the above code, we set the callback function to intval(), which can convert a string into an integer. So array_walk will walk through each element in the $arr array and pass it to intval(), getting a new integer value.

The output result is as follows:

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

We can see that the original array $arr has been successfully converted into an integer array.

To sum up, converting a string array to an integer array is a relatively simple operation. We can use the array_map or array_walk function to accomplish this. It should be noted that the intval() function can convert a string into an integer, so it is a very useful tool.

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