Update multidimensional array from (Y-m) to (Y)

I would like to know if there is any way to change or update a multidimensional array from this

Array ( 
       [AZ] => Array ( [1] => 2020-01 [2] => 2020-02 ) 
       [BY] => Array ( [0] => 2020-03 [1] => 2020-04 ) 
       [CX] => Array ( [1] => 2020-05 [2] => 2020-06 [3] => 2020-07 ) 
       [DW] => Array ( [106] => 2019-01 [107] => 2019-02 [108] => 2019-03)
      ) 

To this

Array ( 
       [AZ] => Array ( [1] => 2020 [2] => 2020 ) 
       [BY] => Array ( [0] => 2020 [1] => 2020 ) 
       [CX] => Array ( [1] => 2020 [2] => 2020 [3] => 2020 ) 
       [DW] => Array ( [106] => 2019 [107] => 2019 [108] => 2019)
      ) 

I don’t know if this is possible but I hope someone can help me

Answer

You can use array_walk_recursive to walk over all the values in the array, changing those that match a YYYY-MM format to YYYY using preg_replace:

array_walk_recursive($array, function (&$v) {
    $v = preg_replace('/^(d{4})-dd$/', '$1', $v);
});

Note we use &$v as the argument to the callback so that we can change the values in the array.

Output:

Array
(
    [AZ] => Array
        (
            [1] => 2020
            [2] => 2020
        )
    [BY] => Array
        (
            [0] => 2020
            [1] => 2020
        )
    [CX] => Array
        (
            [1] => 2020
            [2] => 2020
            [3] => 2020
        )
    [DW] => Array
        (
            [106] => 2019
            [107] => 2019
            [108] => 2019
        )
)

Demo on 3v4l.org