Which of the following best describes what the following Bare Bones program does?
$\begin{array} { l }
\text { copy } \mathrm { X } \text { to } \mathrm { Z } \
\text { clear } \mathrm { X } \
\text { incr } \mathrm { X } \
\text { while } \mathrm { Z } \text { not } 0 \text { : } \
\text { clear } \mathrm { X } \
\text { decr } \mathrm { Z }
\end{array}$
A) It changes the value of X to 1.
B) If the starting value of X is 0, it sets the value of X to 0. Otherwise, it sets the value of X to 1.
C) If the starting value of X is 0, it sets the value of X to 1. Otherwise, it sets the value of X to 0.
D) It ultimately leaves X the same as it was when the program starteD.

Question

Which of the following best describes what the following Bare Bones program does? 
$\begin{array} { l } 
\text { copy } \mathrm { X } \text { to } \mathrm { Z } \
\text { clear } \mathrm { X } \
\text { incr } \mathrm { X } \
\text { while } \mathrm { Z } \text { not } 0 \text { : } \
\text { clear } \mathrm { X } \
\text { decr } \mathrm { Z }
\end{array}$
A) It changes the value of X to 1.
B) If the starting value of X is 0, it sets the value of X to 0. Otherwise, it sets the value of X to 1.
C) If the starting value of X is 0, it sets the value of X to 1. Otherwise, it sets the value of X to 0.
D) It ultimately leaves X the same as it was when the program starteD.

Quizplus · Accepted Answer

The program copies the value of X to Z, clears X, increments X by 1, and then enters a loop that clears X and decrements Z until Z is 0. If X starts as 0, it ends as 1 because the loop runs zero times, leaving the incremented value of X. If X starts as any positive number, the loop runs, clearing X each time, and ends with X set to 0 after the loop exits.

Which of the Following Best Describes What the Following Bare