Question

What does this method do?

void mystery()
{
turnEast();
while( frontIsClear() )
{
while(nextToABeeper())
{
pickBeeper();
}
move();
}
}

A) Walks to the wall.
B) Walks to the wall, picking one beeper at a time.
C) Walks to the wall, clearing all corners on the way.
D) Errors out.

Answer 1

The 'mystery()' method causes a character to turn East, proceed to walk to a wall, and clear all beepers from the corners along the way. The method repeatedly picks up beepers until none are left beside the character, then it moves forward one space and repeats the process until the character cannot move further.

Step-by-step explanation:

The given method mystery() performs the following actions:

1. It first makes the character turn East using the turnEast() method.
2. Then, it begins a loop that will continue as long as the condition frontIsClear() evaluates as true, meaning there is no obstacle directly in front of the character.
3. Within this first loop, there is a nested loop that checks if the character is next to a beeper with nextToABeeper().
4. If the character is next to a beeper, it will enter the nested loop and continue to pick up beepers using the pickBeeper() method until there are no more beepers present.
5. Once there are no more beepers, or if there were none to begin with, the character will proceed to move() forward one space.
6. This process repeats until the character cannot move forward anymore, indicating it has reached a wall.

This sequence of actions corresponds to option C: Walks to the wall, clearing all corners on the way. The method is designed to have the character move east until it hits a wall, picking up any and all beepers found along the way. It should not error out, given that all methods called are assumed to be properly defined elsewhere in the code.