How to remove the key name of multidimensional array in php

In PHP, array is a very common data type. A multidimensional array is an array that contains one or more arrays. In practical applications, we often need to extract data from multi-dimensional arrays and combine and process them. However, when we use multi-dimensional arrays for data processing, the key names in the array may become a limitation. Therefore, how to remove the key names of multi-dimensional arrays and retrieve all element values ​​in the array has become a problem we need to solve.

Here we will introduce some common methods to remove the key names of multi-dimensional arrays.

Method 1: Use the array_values() function

We can use the PHP built-in function array_values() to remove the key names of the multi-dimensional array and retain only the element values. This function is an array function in PHP that can return the values ​​of all values ​​in the array, ignoring the key names, so it can solve our problem.

Next, let’s take a look at the specific code implementation:

$arr  =  array(
            array('name' => '小明', 'age' => 23),
            array('name' => '小红', 'age' => 25)
        );
$new_arr = array();
foreach($arr as $val) {
    $new_arr[] = array_values($val);
}
print_r($new_arr);

Code analysis:

defines a multi-dimensional array $arr, and uses the array_values() function to Its elements become key-value subscripts. Use a foreach loop to traverse the array, convert each array element into an array without a key name using the array_values() function, and store it in the new array $new_arr. Finally, the $new_arr array is printed out by calling the print_r() function.

Method 2: Use the array_map() function

We can also use the array_map() function to remove the key names of multi-dimensional arrays. This function accepts two parameters, one is the callback function and the other is the array to be processed. The callback function is used to process each element and convert it into a new value, while the array map() function returns a new array consisting of the result array obtained after executing the callback function on each element of the original array.

Next let’s take a look at the specific code implementation:

$arr  =  array(
            array('name' => '小明', 'age' => 23),
            array('name' => '小红', 'age' => 25)
        );
$new_arr = array_map('array_values', $arr);
print_r($new_arr);

Code analysis:

We define a multi-dimensional array $arr and an empty array $new_arr . We then apply the callback function array_values() to each element in the array $arr using the array_map() function and store it in the new array $new_arr. Finally, the $new_arr array is printed out by calling the print_r() function.

Method 3: Use for loop traversal

In addition to using built-in functions to process multi-dimensional arrays, we can also use for loop traversal to remove the key names of multi-dimensional arrays. We can achieve the purpose of removing the key name by traversing the array and storing the value of each element in a new array.

Next let's take a look at the specific code implementation:

$arr  =  array(
            array('name' => '小明', 'age' => 23),
            array('name' => '小红', 'age' => 25)
        );
$new_arr = array();
foreach ($arr as $key => $value) {
    $new_item = array();
    foreach($value as $v) {
        $new_item[] = $v;
    }
    $new_arr[] = $new_item;
}
print_r($new_arr);

Code analysis:

defines a multi-dimensional array $arr and traverses it. Then, we define an empty array $new_arr, and use another foreach loop to traverse each element, and take the value from each element and store it in a new array $new_item. Finally, we store the new array $new_item into the new array $new_arr and print out the $new_arr array.

In actual development applications, for different development needs, we can use different methods to solve problems with multi-dimensional arrays. These methods can also refer to the above three methods. Developers can choose according to their own needs. .

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