How Can I Efficiently Remove Duplicate Sub-arrays from a Multidimensional Array in PHP?

Efficient Removal of Duplicate Values from Multidimensional Arrays in PHP

To effectively remove duplicate values from a multidimensional array in PHP, an elegant approach can be employed using array serialization and un-serialization.

Consider the following example array:

Array
(
    [0] => Array
    (
        [0] => abc
        [1] => def
    )

    [1] => Array
    (
        [0] => ghi
        [1] => jkl
    )

    [2] => Array
    (
        [0] => mno
        [1] => pql
    )

    [3] => Array
    (
        [0] => abc
        [1] => def
    )

    [4] => Array
    (
        [0] => ghi
        [1] => jkl
    )

    [5] => Array
    (
        [0] => mno
        [1] => pql
    )

)

To remove duplicates from this array, we can utilize the following code:

$input = array_map("unserialize", array_unique(array_map("serialize", $input)));

This code performs the following steps:

• Serialization: Each sub-array is serialized using the serialize() function, converting it into a unique string representation.
• Uniqueness Check: The array_unique() function is applied to the array of serialized strings, eliminating any duplicates.
• Un-serialization: Finally, the resulting array of unique strings is un-serialized using the unserialize() function, restoring the sub-arrays to their original form.

This approach efficiently removes duplicate values while maintaining the original array structure. It is particularly useful for scenarios where you have large multidimensional arrays and need to quickly eliminate duplicates.

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