[RESOLVED] 2 array

[jeepin81]

So, I have 2 arrays and I need to compare the arrays against each another and if the keys match I need to add up those values of those matching keys.

I'm little lost at how to accomplish this.

Here are my arrays:

// array 1
Array
(
    [45] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
            [3] => 4
            [4] => 7
            [5] => 7
            [6] => 7
            [7] => 7
        )

[47] => Array
    (
        [0] => 1
        [1] => 2
        [2] => 3
        [3] => 4
        [4] => 6
        [5] => 6
        [6] => 6
        [7] => 6
    )

[43] => Array
    (
        [0] => 4
        [1] => 5
        [2] => 4
        [3] => 5
        [4] => 8
        [5] => 8
        [6] => 8
        [7] => 10
    )

[8] => Array
    (
        [0] => 3
        [1] => 4
        [2] => 5
        [3] => 6
        [4] => 10
        [5] => 10
        [6] => 7
        [7] => 8
    )

)

//array 2
Array
(
    [45] => Array
        (
            [0] => 9
            [1] => 9
            [2] => 9
            [3] => 9
            [4] => 6
            [5] => 7
            [6] => 7
            [7] => 7
        )

[47] => Array
    (
        [0] => 8
        [1] => 8
        [2] => 8
        [3] => 8
        [4] => 7
        [5] => 7
        [6] => 7
        [7] => 7
    )

[43] => Array
    (
        [0] => 7
        [1] => 6
        [2] => 9
        [3] => 6
        [4] => 7
        [5] => 7
        [6] => 7
        [7] => 7
    )

[8] => Array
    (
        [0] => 9
        [1] => 9
        [2] => 9
        [3] => 9
        [4] => 7
        [5] => 7
        [6] => 7
        [7] => 7
    )

)

as insight would really be appreciated... Thanks

[bradgrafelman]

If I were doing it, the process might go something like:

1. Use a [man]foreach[/man] loop to loop over one of the arrays (using the '$key => $value' syntax for the foreach construct).

2. Use [man]isset/man or [man]array_key_exists/man to check if that key exists in the other array. If it doesn't, [man]continue[/man] to the next iteration of the foreach loop.

3. Use [man]array_sum/man to sum the value for both sub-arrays.

4. Lather, rinse, repeat

[NogDog]

It's likely I would have done more or less what Brad suggested, but upon thinking about it a bit more, another approach (though not necessarily better) might be something like:

$commonIndexes = array_intersect(array_keys($array1), array_keys($array2));
$results = array();
foreach($commonIndexes as $ix) {
   $results[$ix] = array_sum($array1[$ix]) + array_sum($array2[$ix]);
}
echo "<pre>".print_r($results, 1)."</pre>";

[bradgrafelman]

@: I had actually first thought of using [man]array_intersect_keys/man (similar to what you'd done), but then a nagging voice in the back of my head (who turned out to be my Intro to Algorithms professor... shudder) asked: Why loop through two arrays when only one pass will do?

[jeepin81]

Thanks NogDog & BradG...

Nog your solution worked perfectly and I was able to create same result with Brads insight. Thanks for the lesson guys - I really appreciate it.

Here's what I ended-up with:

$totalPoints = array();
foreach($homeArr as $key=>$value){
	if(array_key_exists($key, $visitArr)){
		$totalPoints[$key] = array_sum($value) + array_sum($visitArr[$key]);
	}else{
		continue;
	}
}
echo "<pre>".print_r($totalPoints, 1)."</pre>";