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English
The array_diff_key() function takes two or more array parameters and returns an array containing keys that exist in the first array but not in the other arrays. The syntax is as follows:
array_diff_key(array $array1, array $array2, array ...$arrays): array
$array1 : The first array, the benchmark array for comparison.
$array2 : The second array, the object to compare the benchmark array.
$arrays : Optional parameter, multiple arrays can be passed into multiple comparisons.
The return result is an array containing key-value pairs that exist in $array1 but not in $array2 .
Suppose we have two configuration arrays that contain the same configuration items, but some configuration items may have differences in key names and contents. With the array_diff_key() function, we can easily find these differences.
Here is a sample code showing how to compare two configuration arrays using array_diff_key() and quickly find inconsistent entries.
<?php
// Configure array 1
$config1 = [
'db_host' => 'localhost',
'db_name' => 'my_database',
'db_user' => 'root',
'db_password' => 'password123',
'api_url' => 'https://m66.net/api/v1',
'cache_enabled' => true,
];
// Configure array 2
$config2 = [
'db_host' => 'localhost',
'db_name' => 'my_database',
'db_user' => 'admin',
'db_password' => 'password123',
'cache_enabled' => true,
'api_url' => 'https://m66.net/api/v2', // Different versions
];
// use array_diff_key() Find differences in configuration
$differences = array_diff_key($config1, $config2);
// Output difference
echo "exist config1 middle，但不exist config2 middle的配置项:\n";
print_r($differences);
?>
Suppose we run the above code, the output will be:
exist config1 middle，但不exist config2 middle的配置项:
Array
(
[api_url] => https://m66.net/api/v1
[db_user] => root
)
From the results, we can see that the values of the db_user and api_url configuration items are different in the two arrays. db_user is modified to admin in config2 , while the version numbers of api_url are different.
With this approach, we can clearly identify the inconsistencies between the two configuration arrays.
In actual development, we may need to compare multiple configuration files or configurations of multiple different environments (for example: development environment, production environment, etc.). Through the array_diff_key() function, developers can easily find different parts that exist between configuration files, which is very helpful for troubleshooting configuration errors or finding missing configuration items.
