Merge two sorted arrays and the resulting array should also be sorted

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My question was:

Let's say you have two arrays of arrays with the same structure but different count of arrays in them:

$arr1 = array(array(1,"b"), array(2,"a"), array(5,"c"));  
$arr2 = array(array(3,"e"));

Now, the data in the $arr1 and $arr2 is sorted, and now what I would like it to merge these two arrays, so I did this:

$res = array_merge($arr1, $arr2);

And then I get an output like this:


But, I would like to have a sorted $res also like this:


I wonder if there's a function in PHP to do this automatically, without me having to write my own function? Or, please advise me on which is the best approach for this if I want to (later on) add sorting by the next parameter so the output would be like this



The answer, by user fieg, was:

You can first merge the arrays and then sort the final array.

You are probably looking for a multi-sort function. I usually use this function (I found this functions somewhere on the internet years ago, credits go to the original author):

 * sort a multi demensional array on a column
 * @param array $array array with hash array
 * @param mixed $column key that you want to sort on
 * @param enum $order asc or desc
function array_qsort2 (&$array, $column=0, $order="ASC") {
    $oper = ($order == "ASC")?">":"<";
    if(!is_array($array)) return;
    usort($array, create_function('$a,$b',"return (\$a['$column'] $oper \$b['$column']);")); 

You can use it like this:

array_qsort2($res, 0, "ASC");
Written by Nikola Brežnjak