L04: Repetition

Question 1

What are the 3 types of loops?

Answer 1

while, do-while, for

Question 2

Describe a while loop.

Answer 2

While a condition is true, the statement is executed repeatedly.

Question 3

What happens when a condition is always true in a while loop?

Answer 3

Infinite loop.

Question 4

Describe a do-while loop.

Answer 4

The statement is executed before the condition is evaluated.

Question 5

What’s the main difference between while and do-while?

Answer 5

The do-while loop executes the statement at least one time.

Question 6

Describe the 4 elements in a for loop.

Answer 6

initialization A. condition B. statement C. update D

for (A; B; D)
C;

Question 7

Are expressions in a for loop optional?

Answer 7

Yes, any part can be omitted, however the semi-colons must remain.
ex. for (int j=0; ; j++)

Question 8

When should we use while vs for.

Answer 8

while is used when we don’t know how many times we want to execute a statement. for is used when we know how many times we want to execute a loop body.

Question 9

for (i=0, sum=0; i<10; sum+=i,i++);
Is this valid syntax?

Answer 9

Yes, the for loop is executed however, no statement is executed.

Question 10

If we want multiple expressions in a for loop what can we use?

Answer 10

Commas separating each expression can be used.
ex. for(i=0, j-1; i<=10; i++, j*=2) –> VALID