array_intersect throws errors when arrays have sub-arrays

Question

I\'m trying to use array_intersect to compare two arrays of arrays.

$start[]=array(
        \'id\'=>1,
        \'name\'=>\'Up\',
        \         


        

Answer 1

Someone else elsewhere suggested array_map and serialize. I ended up coming up with this--which is certainly much easier than nesting and recursion and failing miserably in an attempt to basically rewrite the array_intersect function.

echo '<pre>';

$start[]=array(
        'id'=>1,
        'name'=>'Up',
        'action'=>'up'
);
$start[]=array(
        'id'=>3,
        'name'=>'Down',
        'action'=>'down'
);
$start[]=array(
        'id'=>5,
        'name'=>'Left',
        'action'=>'left'
);
$start[]=array(
        'id'=>2,
        'name'=>'Left',
        'action'=>'left'
);





$end[]=array(
        'name'=>'Up',
        'id'=>1,

        'action'=>'up'
);
$end[]=array(
        'id'=>8,
        'name'=>'Right',
        'action'=>'Right'
);




function serialize_array_values($arr){
    foreach($arr as $key=>$val){
        sort($val);
        $arr[$key]=serialize($val);
    }

    return $arr;
}




$result = array_map("unserialize", array_intersect(serialize_array_values($start),serialize_array_values($end)));

echo "\n\n\n";
echo var_dump($result);


echo '</pre>';

Answer 2

The array_diff and array_intersect convert each element in the primary array in to a string for comparison. If you would like a different comparison, then you could use the callback method with the following built-in functions:

array_uintersect_assoc() - Computes the intersection of arrays with additional index check, compares data by a callback function
array_intersect_uassoc() - Computes the intersection of arrays with additional index check, compares indexes by a callback function
array_uintersect_uassoc() - Computes the intersection of arrays with additional index check, compares data and indexes by a callback functions

I found these by searching PHP.net for the function array_diff and followed the related function links. Its a great way to see alternatives for doing something.