I have an object as below,

{"metaData":[{"name":"a"},{"name":"b"}],"rows":[[1,2],[3,4],[5,6]]}

I would like to change it to

[["a"=>1,"b"=>2],["a"=>4,"b"=>5],["a"=>5,"b"=>6]]

Is there any faster one liner that can convert this without going thru a loop in Laravel ?

CodePudding user response：

You can get the keys with array_column, then map array_combine over the rows.

$keys = array_column($object->metaData, 'name');
$result = array_map(fn($row) => array_combine($keys, $row), $object->rows);

You could make it a one-liner like this, but it's more difficult to read, and it will call array_column for every row instead of just once.

$result = array_map(fn($row) => array_combine(array_column($object->metaData, 'name'), $row), $object->rows);

You need to be sure that each row is the same size as the metadata array or array_combine will fail. Based on the appearance of your object, it looks like this would probably always be true, but it's important to note.

CodePudding user response：

BUT. This is almost a one liner :)

$str = '{"metaData":[{"name":"a"},{"name":"b"}],"rows":[[1,2],[3,4],[5,6]]}';

$obj = json_decode($str);

$obj->rows = array_map( function ($a) {return ['a'=>$a[0], 'b'=>$a[1]];} , $obj->rows);
print_r($obj);
echo json_encode($obj);

RESULT

stdClass Object
(
    [metaData] => Array
        (
            [0] => stdClass Object
                ([name] => a)

            [1] => stdClass Object
                ([name] => b)
        )
    [rows] => Array
        (
            [0] => Array
                ([a] => 1,[b] => 2)

            [1] => Array
                ([a] => 3,[b] => 4)

            [2] => Array
                ( [a] => 5,[b] => 6)
        )
)

{"metaData":[{"name":"a"},{"name":"b"}],"rows":[{"a":1,"b":2},{"a":3,"b":4},{"a":5,"b":6}]}

UPDATE, Using the names form the metaData for the array indexes. Not a one liner any more, but it was fun rangling it

$str = '{"metaData":[{"name":"ali"},{"name":"bill"}],"rows":[[1,2],[3,4],[5,6]]}';

$obj = json_decode($str);

// get array of names
$names = array_map( function ($a) {return $a->name;}, $obj->metaData);

// use it in the array map to get any number of names
$rows = array_map( function ($a) use($names) {
                        for( $x=0; $x<count($names); $x  ) {
                            $ret[] = [$names[$x]=>$a[$x]];
                        }
                        return $ret;
                    }
                , $obj->rows);

$obj->rows = $rows;
print_r($obj);
echo json_encode($obj);

NEW RESULTS

stdClass Object
(
    [metaData] => Array
        (
            [0] => stdClass Object
                (
                    [name] => ali
                )

            [1] => stdClass Object
                (
                    [name] => bill
                )

        )

    [rows] => Array
        (
            [0] => Array
                (
                    [0] => Array
                        (
                            [ali] => 1
                        )

                    [1] => Array
                        (
                            [bill] => 2
                        )

                )

            [1] => Array
                (
                    [0] => Array
                        (
                            [ali] => 3
                        )

                    [1] => Array
                        (
                            [bill] => 4
                        )

                )

            [2] => Array
                (
                    [0] => Array
                        (
                            [ali] => 5
                        )

                    [1] => Array
                        (
                            [bill] => 6
                        )

                )

        )

)
{"metaData":[{"name":"ali"},{"name":"bill"}],"rows":[[{"ali":1},{"bill":2}],[{"ali":3},{"bill":4}],[{"ali":5},{"bill":6}]]}