Switch two items in associative array

Question

Example:

$arr = array(
  \'apple\'      => \'sweet\',
  \'grapefruit\' => \'bitter\',
  \'pear\'       => \'tasty\',
  \'banana\'     => \'yellow\'
)         


        

Answer 1

fwiw here is a function to swap two adjacent items to implement moveUp() or moveDown() in an associative array without foreach()

/**
 * @param array  $array     to modify
 * @param string $key       key to move
 * @param int    $direction +1 for down | -1 for up
 * @return $array
 */
protected function moveInArray($array, $key, $direction = 1)
{
    if (empty($array)) {
        return $array;
    }
    $keys  = array_keys($array);
    $index = array_search($key, $keys);
    if ($index === false) {
        return $array; // not found
    } 
    if ($direction < 0) {
        $index--;
    }
    if ($index < 0 || $index >= count($array) - 1) {
        return $array; // at the edge: cannot move
    } 

    $a          = $keys[$index];
    $b          = $keys[$index + 1];
    $result     = array_slice($array, 0, $index, true);
    $result[$b] = $array[$b];
    $result[$a] = $array[$a];
    return array_merge($result, array_slice($array, $index + 2, null, true)); 
}