How Can I Efficiently Generate All Subsets of an Array in PHP?

Finding the Subsets of an Array in PHP

Determining the closure for all possible subsets of an array is a crucial step in relational database design. To find non-repeating subsets in PHP, consider the following approach:

Subset Generation Using array_merge

function powerSet(array $array) : array {
    // add the empty set
    $results = [[]];

    foreach ($array as $element) {
        foreach ($results as $combination) {
            $results[] = [...$combination, $element];
        }
    }

    return $results;
}

$ATTRIBUTES = ['A', 'B', 'C', 'D'];
$SUBSETS = powerSet($ATTRIBUTES);

This function uses array_merge to generate all possible subsets, including the empty set. The resulting $SUBSETS array will contain all the non-repeating subsets requested in the question:

[
    [],
    ['A'],
    ['B'],
    ['A', 'B'],
    ['C'],
    ['A', 'C'],
    ['B', 'C'],
    ['A', 'B', 'C'],
    ['D'],
    ['A', 'D'],
    ['B', 'D'],
    ['A', 'B', 'D'],
    ['C', 'D'],
    ['A', 'C', 'D'],
    ['B', 'C', 'D'],
    ['A', 'B', 'C', 'D']
]

This method provides a concise and efficient solution for finding subsets of an array in PHP, making it applicable to various data analysis and database design tasks.

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