PHP: Sorting Multidimensional Array by a Sub-Value

This question seeks to sort a multidimensional PHP array based on the "mid" sub-value. To achieve this, the responder recommends employing the usort function, which allows for comparison-based sorting.

Here's how the code would look:

function cmp($a, $b) {
        return $a["mid"] - $b["mid"];
}
usort($arr, "cmp");

The cmp function compares the "mid" values of two array elements and returns -1, 0, or 1 based on the result. This ordering guides the sorting algorithm in usort to arrange the array in ascending order of "mid."

The end result is an array sorted by the "mid" values of its sub-values. Each key in the resulting array corresponds to a "mid" value, with the associated value being the corresponding sub-array.