How to modify the key name of one-dimensional array in php

One-dimensional arrays are often used in PHP programming. Sometimes we need to modify the key names in the array, maybe because the key names do not meet the program requirements, or for better readability and understanding. In PHP, it is very simple to modify the key name of a one-dimensional array. You only need to use the array_combine() and array_keys() functions. Let's introduce it in detail below.

1. array_combine() function

array_combine() function merges two arrays (key array and value array) into one array, with the first array as the new The key in the array, the second array as the value. We can first create an array that needs to be modified, then build a new array to store the new key names, and finally use the array_combine() function to merge the arrays. The sample code is as follows:

<?php
//定义原数组
$array = array(&#39;1&#39;=>'one', '2'=>'two', '3'=>'three');
//定义新的键名数组
$keys = array('a'=>'1', 'b'=>'2', 'c'=>'3');
//合并两个数组
$new_array = array_combine($keys, $array);
print_r($new_array);
?>

In the above code, we first define an original array $key as 1, 2, and 3, and the corresponding values ​​are ‘one’, ‘two’, and ‘three’. Then define a new key array $keys, where key a corresponds to key 1 of the original array, key b corresponds to key 2 of the original array, and key c corresponds to key 3 of the original array. Finally, use the array_combine() function to use $keys as the new key name of the new array, and $array as the value of the new array to fill in the new array $new_array.

The output results are as follows:

Array
(
    [1] => one
    [2] => two
    [3] => three
)

As you can see, using the array_combine() function, we only merge the original array with the new key array, and do not modify the original array itself.

2. array_keys() function

array_keys() function is used to get all the key names of the array. You can directly get all the key names in the original array and then store them. Create a new array and then merge it with the original array to generate a new array. The sample code is as follows:

<?php
//定义原数组
$array = array(&#39;1&#39;=>'one', '2'=>'two', '3'=>'three');
//获取原数组所有键名
$keys = array_keys($array);
//定义新的键名数组
$new_keys = array('a', 'b', 'c');
//合并键名数组和原数组
$new_array = array_combine($new_keys, $array);
print_r($new_array);
?>

In the above code, we first use the array_keys() function to obtain all the key names of the original array $array, and save them to the array $keys. The elements in the array $keys are 1, 2, 3. Then define a new key array $new_keys, the elements of which are a, b, c. Finally, use the array_combine() function to use $keys as the new key name of the new array and $array as the new value of the new array to generate a new array $new_array.

Summary:

It is very simple to modify the key name of a one-dimensional array in PHP. You only need to use the array_combine() function and array_keys() function to achieve it. If you want to modify the key names of the array according to the new key name array, you can directly use the array_combine() function to merge the arrays; if you need to modify all the key names of the original array to new key names, you can first use the array_keys() function Get all the key names of the original array, then convert them into a new key array, and then use the array_combine() function to merge the arrays.

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