Picat Imperative Programming Constructs 4

Question 1

In Picat, what is the scope of a variable assigned inside a `foreach` loop body?

Accepted Answer

It is visible in the enclosing function after the loop ends

Answer

Variables assigned inside a foreach loop body are visible in the surrounding function scope after the loop completes.

Question 2

Which operator tests value equality (not unification) in Picat's imperative code?

Accepted Answer

==

Answer

The == operator tests structural/value equality without binding variables, while = performs unification.

Question 3

What is the Picat equivalent of a C-style `for(i=0; i<n; i++)` loop?

Accepted Answer

foreach(I in 0..n-1)

Answer

Picat uses `foreach(I in 0..n-1)` to iterate over a range, equivalent to C's for loop from 0 to n-1.

Question 4

In Picat, what does the `!` (cut) operator do in an imperative clause?

Accepted Answer

It commits to the current clause, pruning remaining alternatives

Answer

The cut (!) in Picat, inherited from Prolog, commits to the current clause and eliminates remaining choice points.

Question 5

How does Picat handle an `if` condition that raises an exception during evaluation?

Accepted Answer

The exception propagates up the call stack

Answer

Uncaught exceptions in an if condition propagate normally up the call stack just as they would in any other position.

Picat Practice Test