Procedural Programming with C++ Cheat sheet

C++ Loops on One Card: Recall Before It Fills

Loops on one card: can you fill each line before I say it?

Lesson notes

Choose the right loop, and trace loop counters to predict exact iteration counts

Key points

for loop: Use for when you know the count, like printing 1 to 10.
while loop: While checks its loop condition first, so the body may run zero times.
do-while loop: Do-while checks after the body, so it always runs at least once.
Sentinel -1: A sentinel like -1 stops a sum loop when the user enters it.
< vs <= (off-by-one): i < 10 from zero runs ten times; i <= 10 runs eleven.
Trace table: Record each variable per iteration to predict exact output in exams.

Takeaway: Known count: for. Maybe zero: while. At least once: do-while.

Quick check: Which loop runs its body once even when its condition is false at the start?

while
do-while
for

Do-while tests the condition only after executing the body once.

loop conditionsentineloff-by-one error

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