CMap::mergeArray in Yii

Question

I know CMap::mergeArray in Yii merges two array. But I have three array and I want to make them merge through CMap::mergeArray. So how to merge all the three array in Yii framework.

Answer 1

It depends on what you want. The key difference to note is that CMap will overwrite existing keys, which is different from the built in php functions:

If each array has an element with the same string key value, the latter will overwrite the former (different from array_merge_recursive)

If you do CMap::mergeWith as above, you'll just be getting a new array consisting of the 3 arrays as subelements:

For example, given the following structure:

$foo = array (
    'a' => 1,
    'b' => 2,
    'c' => 3,
    'z' => 'does not exist in other arrays',
    );

$bar = array (
    'a' => 'one',
    'b' => 'two', 
    'c' => 'three',
);

$arr = array (
    'a' => 'uno',
    'b' => 'dos',
    'c' => 'tres',
);

Using CMap::mergeWith as follows:

$map = new CMap();
$map->mergeWith (array($foo, $bar, $arr));
print_r($map);

Results in the following:

CMap Object
(
    [_d:CMap:private] => Array
        (
            [0] => Array
                (
                    [a] => 1
                    [b] => 2
                    [c] => 3
                    [z] => does not exist in other arrays
                )

            [1] => Array
                (
                    [a] => one
                    [b] => two
                    [c] => three
                )

            [2] => Array
                (
                    [a] => uno
                    [b] => dos
                    [c] => tres
                )

        )

    [_r:CMap:private] => 
    [_e:CComponent:private] => 
    [_m:CComponent:private] => 
)

If overwriting elements is the preferred behavior, then the following will work:

$map = new CMap ($foo);
$map->mergeWith ($bar);
$map->mergeWith ($arr);
print_r($map);

Which results in:

CMap Object
(
    [_d:CMap:private] => Array
        (
            [a] => uno
            [b] => dos
            [c] => tres
            [z] => does not exist in other arrays
        )

    [_r:CMap:private] => 
    [_e:CComponent:private] => 
    [_m:CComponent:private] => 
)

If, however, you want the data appended, then:

$map = new CMap (array_merge_recursive ($foo, $bar, $arr));
print_r($map);

Will get you there:

CMap Object
(
    [_d:CMap:private] => Array
        (
            [a] => Array
                (
                    [0] => 1
                    [1] => one
                    [2] => uno
                )

            [b] => Array
                (
                    [0] => 2
                    [1] => two
                    [2] => dos
                )

            [c] => Array
                (
                    [0] => 3
                    [1] => three
                    [2] => tres
                )

            [z] => does not exist in other arrays
        )

    [_r:CMap:private] => 
    [_e:CComponent:private] => 
    [_m:CComponent:private] => 
)