Question

I have officially hit a wall and I cannot figure out the solution to this issue. Any help would be much appreciated! I have tried array_intersect() but it just keeps running against the first array in the function, that wont work.

I have an infinite amounts of arrays (I’ll show 4 for demonstration purposes), for example:

// 1.
array(1,2,3,4,5);
// 2.
array(1,3,5);
// 3.
array(1,3,4,5);
// 4.
array(1,3,5,6,7,8,9);

I need to figure out how to search all the arrays and find only the numbers that exist in all 4 arrays. In this example I need to only pull out the values from the arrays – 1, 3 & 5.

PS: In all reality, it would be best if the function could search against a multi dimensional array and extract only the numbers that match in all the arrays within the array.

Thanks so much for your help!

Answer 1

Fun question! This worked:

function arrayCommonFind($multiArray) {

    $result = $multiArray[0];
    $count = count($multiArray);
    for($i=1; $i<$count; $i++) {
        foreach($result as $key => $val) {
            if (!in_array($val, $multiArray[$i])) {
                unset($result[$key]);
            }
        }
    }
    return $result;
}

Note that you can just use $multiArray[0] (or any sub-array) as a baseline and check all the others against that since any values that will be in the final result must necessarily be in all individual subarrays.