How Can I Efficiently Remove Duplicate Sub-Arrays from a Multi-Dimensional Array in PHP?

Removing Duplicate Values from Multi-Dimensional Arrays in PHP

Complex data structures, such as multi-dimensional arrays, often require specialized techniques to manipulate their contents. One common challenge is removing duplicate values across multiple embedded arrays.

PHP Approach

One efficient approach involves using a combination of PHP's array_unique and array_map functions:

$input = array(
    [0] => ['abc', 'def'],
    [1] => ['ghi', 'jkl'],
    [2] => ['mno', 'pql'],
    [3] => ['abc', 'def'],
    [4] => ['ghi', 'jkl'],
    [5] => ['mno', 'pql']
);

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

In this code:

• array_map("serialize", $input) converts each sub-array into a serialized string.
• array_unique removes duplicate serialized strings, resulting in a unique set of values.
• array_map("unserialize", ...) reconstructs the original sub-arrays from the unique serialized strings.

Advantages of this Approach

• Recursive handling of multi-dimensional arrays without the need for intermediate variables.
• Preserves the order of sub-arrays in the output.
• Compatible with different value types within sub-arrays (e.g., strings, integers, arrays).

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