I have an array something with like this

array = [
    1,
    2,
    "Paul John",
    ["PJ", 3, "Mark"],
    "Mark
]

The array variable only contains the data types above. How can I iterate through all the elements including each elements if there is another array within it?

Expectations: I should be able to fetch the values below:

1
2
Paul John
Pj
3
Mark
Mark