How Can I Remove Duplicate Sub-arrays from a Multi-Dimensional PHP Array?

Removing Duplicates from Multi-Dimensional PHP Arrays

In PHP, working with multi-dimensional arrays often involves the need to eliminate duplicate elements. This can be particularly useful when dealing with large datasets where identical values may appear in multiple sub-arrays.

Consider the following example, where we have a 2D array with sub-arrays containing name, email, and other information:

$array = [
    [
        'name' => 'Dave',
        'email' => 'dave@example.com',
    ],
    [
        'name' => 'John',
        'email' => 'john@example.com',
    ],
    [
        'name' => 'Bruce',
        'email' => 'bruce@example.com',
    ],
    [
        'name' => 'John',
        'email' => 'john@example.com',
    ],
];

In this example, we have a duplicate entry with the same email address ('john@example.com'). To remove the duplicate sub-array, we can utilize the uniqueness of array indexes using the following snippet:

$newArr = [];
foreach ($array as $val) {
    $newArr[$val['email']] = $val; 
}
$array = array_values($newArr);

By iterating through the sub-arrays and using the email address as the key for the new array, we overwrite any duplicate values with the last matching sub-array. The array_values() function is then used to reset the array indexes, resulting in a deduplicated array:

$array = [
    [
        'name' => 'Dave',
        'email' => 'dave@example.com',
    ],
    [
        'name' => 'John',
        'email' => 'john@example.com',
    ],
    [
        'name' => 'Bruce',
        'email' => 'bruce@example.com',
    ],
];

This technique effectively removes duplicate values based on the specified key, leaving us with a deduplicated multi-dimensional array.

The above is the detailed content of How Can I Remove Duplicate Sub-arrays from a Multi-Dimensional PHP Array?. For more information, please follow other related articles on the PHP Chinese website!