.net,f# , How do I return formatted string from a function?


How do I return formatted string from a function?

Question:

Tag: .net,f#

I am learning F# so pardon me if this is very basic. I have a function that is supposed to return formatted string:

> let getDoubled x =  sprintf "%d doubled is %d" x, x * 2;;

But when I execute this function it returns the following:

> getDoubled 2;;
val it : (int -> string) * int = (<fun:[email protected]>, 4)

I know I can use .NET's string.Format but was wondering if there was any F# way of doing it?


Answer:

You have an extra comma in your sprintf call, try this:

let getDoubled x =  sprintf "%d doubled is %d" x (x * 2)

The comma means you are constructing a tuple, and this is what you have in your second snippet - a tuple of a function (your partially applied sprintf that's waiting for the second argument) and an int (the result of x*2).


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