Merging two arrays by index

Question

Okay, if feel like this should be really simple and accomplished by a function like array_merge() or array_merge_recursive, but I can't quite figure it out. I have two simple arrays structured like the (simplified) example below. I simply want to merge them into one array based on their index.

$array 1:

Array ( 
  [0] => Array ( 
        [ID] => 201 
        [latLng] => 45.5234515, -122.6762071 
  )  
  [1] => Array ( 
        [ID] => 199 
        [latLng] => 37.7931446, -122.39466520000002 
  )
) 

et cetera…

$array2 :

Array ( 
  [0] => Array ( 
        [distance] => 1000 
        [time] => 10 
  )  
  [1] => Array ( 
        [distance] => 1500 
        [time] => 15 
  )
) 

$desiredResult :

Array ( 
  [0] => Array ( 
        [ID] => 201 
        [latLng] => 45.5234515, -122.6762071 
        [distance] => 1000 
        [time] => 10 
 )  
  [1] => Array ( 
        [ID] => 199 
        [latLng] => 37.7931446, -122.39466520000002 
        [distance] => 1500 
        [time] => 15 
 )
) 

When I try to merge these using merge functions, I can only get this:

$unDesiredResult:

Array ( 
  [0] => Array ( 
        [ID] => 201 
        [latLng] => 45.5234515, -122.6762071 
  )  
  [1] => Array ( 
        [ID] => 199 
        [latLng] => 37.7931446, -122.39466520000002 
  )
  [2] => Array ( 
        [distance] => 1000 
        [time] => 10 
  )  
  [3] => Array ( 
        [distance] => 1500 
        [time] => 15 
  )
) 

Do I need to loop through to push the second set into the first, or can this be done with an existing function?

Answer 1

I don't think there is a function to do this for you, you're gonna have to loop.

$result = array();
foreach($array1 as $key=>$val){ // Loop though one array
    $val2 = $array2[$key]; // Get the values from the other array
    $result[$key] = $val + $val2; // combine 'em
}

Or you can push the data into $array1, so you need to make a 3rd array:

foreach($array1 as $key=>&$val){ // Loop though one array
    $val2 = $array2[$key]; // Get the values from the other array
    $val += $val2; // combine 'em
}

Answer 2

You'll need to use a loop. Try creating a function:

function addArray( array &$output, array $input ) {
    foreach( $input as $key => $value ) {
        if( is_array( $value ) ) {
            if( !isset( $output[$key] ) )
                $output[$key] = array( );
            addArray( $output[$key], $value );
        } else {
            $output[$key] = $value;
        }
    }
}

Then:

$combinedArray = array( );
addArray( $combinedArray, $array1 );
addArray( $combinedArray, $array2 );