Fsharp: String

What is String

• String type's value is sequence of Unicode Characters.
• String is immutable. (once created, it cannot change.)
• string is an alias for System.String in dotnet.

Single Quoted String

• String can be quoted by QUOTATION MARK. E.g. "abc"
• Inside, backslash has special meaning, known as Escape Sequence. E.g. \n means a newline, \" is QUOTATION MARK.
• Backslash at end of line has special meaning. It joins next line and removes any white space in beginning of next line.

// single quote string
let xx = "aa bb"
printfn "%s" xx
// aa bb

// single quote string with literal newline
let xx = "aa
bb"
printfn "%s" xx
(*
aa
bb
*)

// single quote string with escape sequence
let xx = "line 1\nline 2"
printfn "%s" xx
(*
line 1
line 2
 *)

// backslash at end of line means join lines
let xx = "aa\
   bb"
printfn "%s" xx
// aabb

// single quote string with embeded QUOTATION MARK
let xx = "he said \"this\" and \"that\"."
printfn "%s" xx
// he said "this" and "that".

Triple Quoted string (Real Verbatim)

• Syntax is 3 quotation marks. E.g. """abc"""
• Backslash has no special meaning.

// triple quoted string example
let xx =  """some thing"""
printfn "%s" xx
// some thing

// backslash has no special meaning
let xx =  """some\nthing"""
printfn "%s" xx
// some\nthing

// backslash at end of line, no special meaning
let xx = """aa\
   bb"""
printfn "%s" xx
(*
aa\
   bb
 *)

// triple quoted string, example of multiple lines
let xx =  """some thing
in the water"""
printfn "%s" xx
(*
some thing
in the water
*)