In F#, functions work like data types. You can declare and use a function in the same way as any other variable.
You can define a simple F# program that prints text on the console in the following different ways.
An F# application does not have any specific entry point. The compiler executes all top-level statements in the file from top to bottom.
You can use
printfn to print a text message on a console without using any entry point, as shown below.
printfn "Welcome to F# Tutorial."
You can also print a text message on the console using
Console.WriteLine by including the
open System; Console.WriteLine("Welcome to F# Tutorial.")
You can also call the
printfn inside a class as shown in the below example.
type Program() = class do printfn "Welcome to F# Tutorial." end new Program()
printfn can be used inside a function, as shown in the below example.
let myFunc = printfn "Welcome to F# Tutorial." myFunc
To follow procedural programming style, many applications keep a single top-level statement that calls the main loop as shown below.
open System let message = "Welcome to F# Tutorial." [<EntryPoint>] let main argv = Console.WriteLine(message) 0 // return an integer exit code
openstatements that are used to import namespaces.