Question 1

Calculate 3.0 to the power of 4.0.

3.0 ** 4.0

val it: float = 81.0

Question 2

Assign the integer 1 to a value called a.

let a = 1

val a: int = 1

Question 3

Write a function named add3 that adds 3.0 to any float input.

let add3 x = x + 3.0

val add3: x: float -> float

Question 4

Take the following two-parameter function:

let multiply (x:float) (y:float) = x * y

Use the above function and partial application to define a new function called multiply2 that multiplies its input by 2.0.

let multiply2 = multiply 2.0

val multiply2: (float -> float)

Question 5

Given a tuple (1.0,2.0), assign the second element to a value named b.

let b = snd (1.0, 2.0)

val b: float = 2.0

let (_, b1) = (1.0, 2.0)

val b1: float = 2.0

Question 6

Create a tuple where the first, second, and third elements are "a", 1, and 2.0.

("a", 1, 2.0)

val it: string * int * float = ("a", 1, 2.0)

Question 7

Define a record type named Record1 that has a string Id field and a float Y field.

type Record1 = { Id : string; Y : float }

type Record1 =
  {
    Id: string
    Y: float
  }

Question 8

Given the type signature val a : float = 2.0, what is the type of value a?

Question 9

Create a record type named Record2. It should have two integer fields X and Y. Create an instance of the record where X = 4 and Y = 2.

type Record2 = { X : int; Y : int }
{ X = 4; Y = 2}

type Record2 =
  {
    X: int
    Y: int
  }
val it: Record2 = { X = 4
                    Y = 2 }

Question 10

Explain why this expression gives an error when you try to run it: 4 + 7.0

Question 11

Create a list where the elements are 1, 2, and 3.

[ 1; 2; 3 ]

val it: int list = [1; 2; 3]

[ 1 .. 3 ]

val it: int list = [1; 2; 3]

[ for i = 1 to 3 do i ]

val it: int list = [1; 2; 3]

Question 12

Given the below list, use printfn to print the whole list to standard output using the structured plaintext formatter.

The list to print:

[1; 2; 3]

[1; 2; 3] |> (printfn "%A")

[1; 2; 3]

Question 13

Given the tuple ("hi", false, 20.321, 4), use printfn and the tuple to print the following string to standard output: "hi teacher, my False knowledge implies that 4%=0020.1"

String formatting documentation will be useful.

let (xString, xBool, xFloat, xInt) = ("hi", false, 20.321, 4)

val xString: string = "hi"
val xInt: int = 4
val xFloat: float = 20.321
val xBool: bool = false

printfn $"{xString} teacher, my {xBool} knowledge implies that {xInt}%%=%06.1f{xFloat}"

hi teacher, my False knowledge implies that 4%=0020.3

printfn "%s teacher, my %b knowledge implies that %i%%=%06.1f" xString xBool xInt xFloat

hi teacher, my false knowledge implies that 4%=0020.3