Consolidating specific values in multidimensional array - php

Question

I have an array of arrays consisting of date, login name, and time (length of time in ms). Here is what it vaguely looks like:
[0]=>
[0]=> "2015-09-06"
[1]=> "user1"
[2]=> "8947226"
[1]=>
[0]=> "2015-09-06"
[1]=> "user1"
[2]=> "6664923"
[2]=>
[0]=> "2015-09-24"
[1]=> "user2"
[2]=> "654654"
I'm trying to make it so that if the date and the login are both the same as another, it adds the time together. So it will look like:
[0]=>
[0]=> "2015-09-06"
[1]=> "user1"
[2]=> "15612149"
[1]=>
[0]=> "2015-09-24"
[1]=> "user2"
[2]=> "654654"
I think my main problem is how to search the array because they won't necessarily be in order by date or login, they're all random.
First I was doing this because I thought they would be in some sort of order:
if ($i != 0) {
if ($date == $bigArray[$prevIndex][0] && $login == $bigArray[$prevIndex][1]) {
$bigArray[$prevIndex][2] += $time;
} else {
array_push($bigArray, array($date, $login, $time));
$prevIndex++;
}
} else {
array_push($bigArray, array($date, $login, $time));
}
But that doesn't work since they are in a random order. I've tried to sort the array first as well, and that's not working.

Answer 1

There's a way to do it, but maybe it's not the best.
<?php
$arr = [];
$arr[0] = ["2015-09-26", "user1", "8947226"];
$arr[1] = ["2015-09-26", "user1", "6664923"];
$arr[2] = ["2015-09-24", "user2", "654654"];
// Variable to store the new values.
$arr2 = [];
// Scrolls through the array
foreach($arr as $ar) {
// Creates a key to identify date and login
$key = md5($ar[0].$ar[1]);
// Checks whether the value is already in the variable $arr2
if (isset($arr2[ $key ])) {
// If so, adds the values in ms
$arr2[ $key ][2] += $ar[2];
} else {
$arr2[ $key ] = $ar;
}
}
// Use the array_values to display only the values (without displaying the $key);
var_export( array_values($arr2) );