How to Sort Multidimensional Arrays in PHP by Timestamp?

Sorting Multidimensional Arrays in PHP based on Timestamp

Sorting multidimensional arrays in PHP can be achieved using the usort function. This function allows sorting based on a user-defined comparison function.

To sort an array based on the Unix timestamp value of the fourth element (x[4]), define a comparison function as follows:

<code class="php">function compare($x, $y) {
    if ($x[4] == $y[4]) {
        return 0;
    } elseif ($x[4] < $y[4]) {
        return -1;
    } else {
        return 1;
    }
}</code>

This function checks if the timestamp values are equal (returns 0), less than -1, or greater than 1.

Once the comparison function is defined, call it with usort like this:

<code class="php">usort($nameOfArray, 'compare');</code>

This will sort the array $nameOfArray ascendingly based on the Unix timestamp values in x[4] of each subarray.

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