How to Sort a Multidimensional Array by a Specific Key Using PHP\'s usort()?

Sorting a Multidimensional Array by a Specific Key

In the realm of programming, sorting data is a fundamental operation, particularly when working with arrays. When dealing with multidimensional arrays, the task of sorting by a specific key can arise.

Let's consider the need to sort a multidimensional array based on a key, represented as [status] in your example array. To achieve this, we can leverage the usort() function in PHP, which requires a comparison function as an argument.

Comparison Function

The comparison function for usort() determines the sorting order by comparing two array elements. In this case, we want to compare the [status] values of the two arrays a and b:

function cmp($a, $b) {
    if ($a['status'] == $b['status']) {
        return 0;
    }
    return ($a['status'] < $b['status']) ? -1 : 1;
}

• If both arrays have the same [status] value, it returns 0.
• If array a's [status] is less than array b's, it returns -1.
• If array a's [status] is greater than array b's, it returns 1.

Sorting the Array

Now that we have defined our comparison function, we can apply it to sort the array using usort():

usort($array, "cmp");

This command will modify the original $array in-place, sorting it based on the comparison function.

By altering the comparison function, you can sort the array on any key you desire, providing flexible sorting capabilities for your multidimensional arrays.

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