Do–while loop in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a do-while loop that prints "Hello" once.

C++

int main() {
    int count = 0;
    do {
        std::cout << "Hello\n";
        count++;
    } while ([1]);
    return 0;
}

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

Acount < 1

Bcount > 1

Ccount == 1

Dcount != 0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a condition that is false initially, so the loop never repeats.

Using 'count > 1' which is false at the start, causing no repetition.

The condition count < 1 ensures the loop runs once and then stops.

2fill in blank

medium

Complete the code to keep asking the user for a number until they enter 0.

C++

int main() {
    int num;
    do {
        std::cout << "Enter a number (0 to stop): ";
        std::cin >> num;
    } while ([1]);
    return 0;
}

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

Anum == 0

Bnum != 0

Cnum > 0

Dnum < 0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'num == 0' which would stop the loop immediately.

Using conditions that only check for positive or negative numbers.

The loop continues while the number is not zero, so the condition is num != 0.

3fill in blank

hard

Fix the error in the do-while loop condition to repeat while x is less than 5.

C++

int main() {
    int x = 0;
    do {
        std::cout << x << " ";
        x++;
    } while (x [1] 5);
    return 0;
}

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

A>

B==

C<

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' which would cause the loop to never run.

Using '==' which only runs when x equals 5.

The loop should continue while x < 5 to print numbers 0 to 4.

4fill in blank

hard

Fill both blanks to create a do-while loop that prints numbers from 1 to 3.

C++

int main() {
    int i = 1;
    do {
        std::cout << i << " ";
        i[1];
    } while (i [2] 3);
    return 0;
}

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

A++

B--

C<=

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--' which decreases i and causes an infinite loop.

Using '>' or '>=' which would not print numbers 1 to 3 correctly.

Increment i with ++ and continue while i is less than or equal to 3.

5fill in blank

hard

Fill all three blanks to create a do-while loop that sums numbers from 1 to 5.

C++

int main() {
    int sum = 0;
    int num = 1;
    do {
        sum [1] num;
        num [2];
    } while (num [3] 5);
    std::cout << sum << std::endl;
    return 0;
}

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

A+=

B++

C<=

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' or '--' which decreases values incorrectly.

Using '<' instead of '<=' which misses the last number 5.

Use sum += num; to add num to sum, increment num with ++, and continue while num is less than or equal to 5.