Python For Loop Tracing Practice

For loops are the backbone of AP Computer Science and phone-screen warm-ups. Interviewers test whether you track the loop variable, off-by-one bounds, and side effects inside the body. Work through the static examples below, then generate unlimited AI problems.

Example problems

s = 0
for i in range(2, 8, 2):
    s += i
print(s)

for i in range(2):
    for j in range(3):
        print(i, j, end=' ')

a = [1, 2, 3]
for x in a:
    a.append(x * 2)
print(len(a))