for the example, I have an array

```
Array(
[0] => Array
    (
        [0] => "0"
        [1] => "1"
    )
[1] => 
[2] => Array
    (
        [4] => "4"
        [5] => "5"
        [7] => "7"
    )

```

and I want to find empty array value, and replace it.

```
[1] => data not found

```