F# Tutorial on F# Data Types
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the data types in f# can be classified as follows −

  • integral types
  • floating point types
  • text types
  • other types

integral data type

the following table provides the integral data types of f#. these are basically integer data types.

f# type size range example remarks
sbyte 1 byte -128 to 127

42y

-11y

 8-bit signed integer
byte 1 byte 0 to 255

42uy

200uy

 8-bit unsigned integer
int16 2 bytes -32768 to 32767

42s

-11s

 16-bit signed integer
uint16 2 bytes 0 to 65,535

42us

200us

 16-bit unsigned integer
int/int32 4 bytes -2,147,483,648 to 2,147,483,647

42

-11

 32-bit signed integer
uint32 4 bytes 0 to 4,294,967,295

42u

200u

 32-bit unsigned integer
int64 8 bytes -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

42l

-11l

 64-bit signed integer
uint64 8 bytes 0 to 18,446,744,073,709,551,615

42ul

200ul

 64-bit unsigned integer
bigint at least 4 bytes any integer

42i

1499999

9999999

9999999

9999999

9999i

 arbitrary precision integer

example

(* single byte integer *)
let x = 268.97f
let y = 312.58f
let z = x + y

printfn "x: %f" x
printfn "y: %f" y
printfn "z: %f" z

(* unsigned 8-bit natural number *)

let p = 2uy
let q = 4uy
let r = p + q

printfn "p: %i" p
printfn "q: %i" q
printfn "r: %i" r

(* signed 16-bit integer *)

let a = 12s
let b = 24s
let c = a + b

printfn "a: %i" a
printfn "b: %i" b
printfn "c: %i" c

(* signed 32-bit integer *)

let d = 212l
let e = 504l
let f = d + e

printfn "d: %i" d
printfn "e: %i" e
printfn "f: %i" f

when you compile and execute the program, it yields the following output −

x: 1
y: 2
z: 3
p: 2
q: 4
r: 6
a: 12
b: 24
c: 36
d: 212
e: 504
f: 716

floating point data types

the following table provides the floating point data types of f#.

f# type size range example remarks
float32 4 bytes ±1.5e-45 to ±3.4e38

42.0f

-11.0f

 32-bit signed floating point number (7 significant digits)
float 8 bytes ±5.0e-324 to ±1.7e308

42.0

-11.0

 64-bit signed floating point number (15-16 significant digits)
decimal 16 bytes ±1.0e-28 to ±7.9e28

42.0m

-11.0m

 128-bit signed floating point number (28-29 significant digits)
bigrational at least 4 bytes any rational number.

42n

-11n

 arbitrary precision rational number. using this type requires a reference to fsharp.powerpack.dll.

example

(* 32-bit signed floating point number *)
(* 7 significant digits *)

let d = 212.098f
let e = 504.768f
let f = d + e

printfn "d: %f" d
printfn "e: %f" e
printfn "f: %f" f

(* 64-bit signed floating point number *)
(* 15-16 significant digits *)
let x = 21290.098
let y = 50446.768
let z = x + y

printfn "x: %g" x
printfn "y: %g" y
printfn "z: %g" z

when you compile and execute the program, it yields the following output −

d: 212.098000
e: 504.768000
f: 716.866000
x: 21290.1
y: 50446.8
z: 71736.9

text data types

the following table provides the text data types of f#.

f# type size range example remarks
char 2 bytes u+0000 to u+ffff

'x'

'\t'

 single unicode characters
string 20 + (2 * string's length) bytes 0 to about 2 billion characters

"hello"

"world"

 unicode text

example

let choice = 'y'
let name = "zara ali"
let org = "tutorials point"

printfn "choice: %c" choice
printfn "name: %s" name
printfn "organisation: %s" org

when you compile and execute the program, it yields the following output −

choice: y
name: zara ali
organisation: tutorials point

other data types

the following table provides some other data types of f#.

f# type size range example remarks
bool 1 byte only two possible values, true or false

true

false

 stores boolean values

example

let trueval = true
let falseval = false

printfn "true value: %b" (trueval)
printfn "false value: %b" (falseval)

when you compile and execute the program, it yields the following output −

true value: true
false value: false
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