php - 合并关联数组时计算空白

Question

我正在尝试合并这两个数组

$arr1 = array('a' => "1", 'b' => "2", 'c' => "3");
$arr2 = array('a' => "9", 'b' => "8", 'd' => "7");

变成这样的数组

$arr1 = array(  
   'a' => array("1", "9"),  
   'b' => array("2", "8"),  
   'c' => array("3", ""),
   'd' => array("", "7")
);

棘手的部分是空白。我需要将它们保存到位。

谢谢

Answer 1

function merge()
{

    $array_of_arrays = func_get_args();

    //get all the unique keys    
    $final_array_keys = array_keys( call_user_func_array( "array_merge", $array_of_arrays ) );

    //make final array
    $final_array = array();
    foreach( $final_array_keys as $key ) {
        foreach( $array_of_arrays as $current_array ) {
            $final_array[$key][] = array_key_exists( $key, $current_array ) ? $current_array[$key] : "";
        }
    }
    return $final_array;

}