Combine Sub-array values into a single array withing an array

Question

I may not word this issue properly, so here's what am trying to achieve.

array { 
    [0]=> { 
        ["Abilities"]=> { ["Numerical"]=> 3 } 
    } 
    [1]=> { 
        ["Abilities"]=> { ["Verbal"]=> 1 } 
    } 
    [2]=> { 
        ["Domain"]=> { ["Programming"]=> 0 } 
    } 
} 

to

array { 
    [0]=> { 
        ["Abilities"]=> { ["Numerical"]=> 3 ["Verbal"]=> 1 } 
    } 
    [1]=> { 
        ["Domain"]=> { ["Programming"]=> 0 } 
    } 
} 

I get this array from an external source so I need optimized this way to use it.

Answer 1

The array you're getting from an external source is like a set of separate branches you need to merge into a single tree. You can use a recursive function to create the "optimized" structure you're going for. A recursive approach should work regardless of the depth of each branch.

function merge_branches(array $branches): array
{
    $merge = function ($node, &$tree) use (&$merge) {
        if (is_array($value = reset($node))) {
            $merge($value, $tree[key($node)]);        // merge branch node recursively
        } else {
            $tree[key($node)] = $value;               // set leaf node to value
        }
    };

    $tree = [];
    foreach ($branches as $branch) {
        $merge($branch, $tree);
    }
    return $tree;
}

$optimized = merge_branches($external);