Question

can someone help me answer the following #Fsharp multiple choice questions along with explanations for each question please.

7. How does F# interpret the type int * bool -> string list? Select one:

a. (int * (bool -> string)) list

b. ((int * bool) -> string) list

c. int * (bool -> (string list))

d. (int * bool) -> (string list)

8. Let F# function foo be defined as follows:

let rec foo = function

| (xs, []) -> xs | (xs, y::ys) -> foo (xs@[y], ys)

If foo is supposed to append its two list parameters, which of the following is true? Select one:

a. foo fails Step 1 of the Checklist for Programming with Recursion.

b. foo fails Step 2 of the Checklist for Programming with Recursion.

c. foo fails Step 3 of the Checklist for Programming with Recursion.

d. foo satisfies all three steps of the Checklist for Programming with Recursion.

11. Which of the following is the type that F# infers for (fun f -> f 17)? Select one:

a. ('a -> 'b) -> 'b

b. (int -> int) -> int

c. (int -> 'a) -> 'a

d. ('a -> 'a) -> 'a

12. Which of the following has type int -> int list? Select one:

a. (@) [5]

b. [fun x -> x+1]

c. fun x -> 5::x

d. fun x -> x::[5]

13. What type does F# infer for the expression (3, [], true) ? Select one:

a. int * 'a list * bool

b. int * 'a * bool

c. int * int list * bool

d. Type error.

Answer 1

How does F# interpret the type int * bool -> string list? Select one:

Answer:
a. (int * (bool -> string)) list

Explantion:

Because here the first string is going to get validate and then it is taken by the int finally convert to list.

8.let rec foo = function

| (xs, []) -> xs | (xs, y::ys) -> foo (xs@[y], ys)

If foo is supposed to append its two list parameters, foo satisfies all three steps of the Checklist for Programming with Recursion.

Answer: D

11. F# infers for (fun f -> f 17)

Answer:

b. (int -> int) -> int

12. Which of the following has type int -> int list?

Answer:

c. fun x -> 5::x

13. F# infer for the expression (3, [], true)

Answer:D

d. Type error.

Have a great day.