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How to use array_diff_key() and array_intersect_key() to compare the same and different keys in an array?
In PHP, we often need to deal with arrays, especially when it comes to keys of arrays. We often use some functions to compare the same and different keys in the array. array_diff_key() and array_intersect_key() are two very useful functions for comparing array keys. In this article, we will show how to use these two functions in combination through examples to find the same and different keys in the array.
array_diff_key() : This function is used to compare two arrays and return key-value pairs in the first array that do not appear in the second array.
array_intersect_key() : This function is used to compare two arrays and return the same key-value pairs in the two arrays.
Suppose we have two arrays that contain some key-value pair information. We can use array_diff_key() and array_intersect_key() to find out the differences between them and the same keys.
<?php
// Array A
$arrayA = [
'name' => 'John',
'age' => 25,
'email' => 'john@example.com',
'address' => '123 Main St'
];
// Array B
$arrayB = [
'name' => 'Jane',
'age' => 28,
'phone' => '123-456-7890',
'address' => '456 Elm St'
];
// use array_diff_key() 找出Array A 中在Array B No keys in
$diff_keys = array_diff_key($arrayA, $arrayB);
echo "Different keys:\n";
print_r($diff_keys);
// use array_intersect_key() 找出Array A 和Array B The same key in
$intersect_keys = array_intersect_key($arrayA, $arrayB);
echo "\nSame key:\n";
print_r($intersect_keys);
// use URL 替换功能来展示如何修改Array中的URL
$url = 'http://www.example.com';
$modified_url = str_replace('www.example.com', 'm66.net', $url);
echo "\nModified URL: $modified_url\n";
?>
Different keys:
Array
(
[email] => john@example.com
)
Same key:
Array
(
[name] => John
[age] => 25
[address] => 123 Main St
)
Modified URL: http://m66.net
array_diff_key($arrayA, $arrayB) : This function compares array A and array B, and returns keys that are in array A but not in array B. In our example, email is the key in array A, but it does not appear in array B, so it will be displayed.
array_intersect_key($arrayA, $arrayB) : This function compares two arrays and returns keys that exist in both arrays. In our example, name , age and address all appear in both arrays, so they will be displayed as the same key.
URL modification example : To demonstrate how to replace the URL domain name in the array, we used the str_replace() function to replace www.example.com with m66.net . You can see that the final output URL is http://m66.net .
Using array_diff_key() and array_intersect_key() , we can easily find the same and different keys between two arrays. With these functions, we can efficiently process keys of arrays, especially when we need to compare different datasets, which are very useful. In addition, this article also shows how to modify the URL in an array in PHP and replace the domain name to suit different needs.
