I have an `initalArray` that looks like this:

initailArray: ["a", "b", "c", "d"]

Say I want to convert `a -> apple`, `b -> berry` `c -> cat` and `d -> dog`

so my newArray should look like this:

```
newArray: ["apple", "berry", "cat", "dog"]

```

Is there a way I could do this? I think I need to use `if` or `switch`. But 
don't know exactly how.