Remove key values ​​from php two-dimensional array

In PHP, array is a very important data structure. In actual development, two-dimensional arrays are often used. Sometimes, we need to remove the key values ​​​​in the two-dimensional array and only take the values ​​​​in the array. This article will introduce how to implement the method of removing key values ​​from a two-dimensional array in PHP.

1. foreach loop traversal

The simplest way to remove the key values ​​​​in the php two-dimensional array is to use a foreach loop to traverse the array. The following is an implemented code example:

<?php
$students = array(
    array('name' => 'Tom', 'age' => 18),
    array('name' => 'Jerry', 'age' => 20),
    array('name' => 'Mike', 'age' => 22)
);

foreach ($students as $student) {
    echo $student['name'] . ' ' . $student['age'] . '<br>';
}
?>

A two-dimensional array $students is defined here, which contains three subarrays: Tom, Jerry and Mike. Then it traverses the $students array through a foreach loop and outputs the name and age values ​​of each sub-array to the page.

2. array_map() function processing

Another way to remove key values ​​from a PHP two-dimensional array is to use the array_map() function. What this function does is pass all array values ​​as parameters to the callback function and then return a new array. The following sample code shows how to use the array_map() function to process a two-dimensional array:

<?php
$students = array(
    array('name' => 'Tom', 'age' => 18),
    array('name' => 'Jerry', 'age' => 20),
    array('name' => 'Mike', 'age' => 22)
);

$result = array_map(function($student) {
    return array_values($student);
}, $students);

print_r($result);
?>

A two-dimensional array $students is defined here, and then the key value of each sub-array is removed through the array_map() function. The specific implementation is to use an anonymous function to pass the subarray to the array_values() function, which will return a new array containing only values. Finally, print the results to the page.

3. Use the array_column() function

In PHP7.0 version, a new function array_column() is introduced, which can simplify the code to implement PHP two-dimensional array without key values. . The following is a code example for implementing this method:

<?php
$students = array(
    array('name' => 'Tom', 'age' => 18),
    array('name' => 'Jerry', 'age' => 20),
    array('name' => 'Mike', 'age' => 22)
);

$result = array_column($students, null);

print_r($result);
?>

A two-dimensional array $students is also defined here. Then use the array_column() function to extract the value of each subarray in the $students array and return a new array. The null parameter means to extract all values ​​and remove the key names. Finally, print the results to the page.

Summary

The above are three ways to remove key values ​​from a two-dimensional array in PHP. Whether it is foreach loop traversal, using the array_map() function or using the array_column() function, it is easy to implement. Different methods can be selected according to specific application scenarios.

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