F#: check if a value is an array of strings, an array of arrays of string or a string

Question

I need use match to check if a value is an array of strings or a string. I've tried something in the vain of

| :? string[] -> ..
| :? string -> ..
| :? array<string[]> -> ..

but invain.

Any help?

Answer 1

You need to modify the syntax slightly, but you were almost correct

let fn (arg:obj) = 
    match arg with
    | :? string as str -> printfn "string"
    | :? (string[]) as arr -> printfn "string array"