Do–while loop in C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print numbers from 1 to 3 using a do–while loop.

C

int i = 1;
do {
    printf("%d\n", i);
    i[1];
} while (i <= 3);

Drag options to blanks, or click blank then click option'

A-

B--

C+=

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--' decreases the value, causing an infinite loop.

Using '-' alone is a subtraction operator but needs a number.

Using '+=' without a number is incomplete.

The operator ++ increases i by 1 each time, allowing the loop to count from 1 to 3.

2fill in blank

medium

Complete the code to ensure the loop runs at least once and stops when count is 5.

C

int count = 0;
do {
    printf("Count: %d\n", count);
    count++;
} while ([1] < 5);

Drag options to blanks, or click blank then click option'

Acount

Bcount++

Ccount--

D++count

Attempts:

3 left

💡 Hint

Common Mistakes

Using count++ or ++count in the condition changes the variable unexpectedly.

Using count-- decreases the value, causing wrong loop behavior.

The condition count < 5 checks the current value of count to decide if the loop should continue.

3fill in blank

hard

Fix the error in the do–while loop condition to avoid an infinite loop.

C

int n = 10;
do {
    printf("%d\n", n);
    n--;
} while (n [1] 0);

Drag options to blanks, or click blank then click option'

A==

B<

C>

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' stops the loop after printing only 10 because after n-- , n=9 which is not < 0.

Using '==' stops the loop after printing only 10 because after n-- , n=9 which != 0.

The loop should continue while n is greater than 0 to count down properly.

4fill in blank

hard

Fill both blanks to create a do–while loop that prints even numbers from 2 to 8.

C

int num = 2;
do {
    printf("%d\n", num);
    num [1] 2;
} while (num [2] 8);

Drag options to blanks, or click blank then click option'

A+=

B-=

C<=

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-=' decreases the number, causing an infinite loop.

Using '>' or '>=' in the condition causes the loop to never run or run infinitely.

Use num += 2 to increase by 2 each time, and num <= 8 to stop after printing 8.

5fill in blank

hard

Fill all three blanks to create a do–while loop that prints numbers from 5 down to 1.

C

int val = [1];
do {
    printf("%d\n", val);
    val [2] 1;
} while (val [3] 1);

Drag options to blanks, or click blank then click option'

A5

B-=

C>=

D+=

Attempts:

3 left

💡 Hint

Common Mistakes

Starting at 1 instead of 5 causes the loop to print only once.

Using '+=' increases the value, causing an infinite loop.

Using '<=' in the condition causes the loop to run infinitely.

Start val at 5, decrease it by 1 each loop with -=, and continue while val >= 1.