Question

In Racket, reversing a list lst can be accomplished with a fold: (foldr cons ’() lst).

a. True
b. False
In Racket, set! and display are both effectful/impure computations.
a. True
b. False

Answer 1

Reversing a list in Racket using a fold can be done with (foldr cons ’() lst), which is true. In Racket, set! and display are both effectful computations, which is also true.

Step-by-step explanation:

In Racket, reversing a list lst can be accomplished with a fold: (foldr cons ’() lst). The correct answer is a. True. Using the foldr function with cons and an empty list as the accumulator, each element of the original list is consed (i.e., added) to the accumulator in reverse order, resulting in a reversed list.

In Racket, set! and display are both effectful/impure computations. The correct answer is a. True. The set! function is used to change the value of a variable, which is an impure operation since it modifies program state. The display function is used to output a value to the console, which is also an impure operation as it produces a side effect.