Fsharp: String Operations

String Index

syntax

str[n]

str.[n]

let xx = "abc"[0]
printfn "%c" xx
// a

String Slice (substring)

syntax

str[n..m]

let xx = "abcdefghijklmnopqrstuvwxyz"[0..6]
printfn "%s" xx
// abcdefg

Join String

str + str

printfn "%s" ("abc" + "def")
// abcdef