Why input and output are required in C++ - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print a message to the screen.

C++

#include <iostream>

int main() {
    std::cout [1] "Hello, world!" << 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 >> instead of << for output.

Using + or -- which are not output operators.

In C++, << is used to send output to the screen using std::cout.

2fill in blank

medium

Complete the code to read an integer from the user.

C++

#include <iostream>

int main() {
    int number;
    std::cout << "Enter a number: ";
    std::cin [1] number;
    std::cout << "You entered: " << number << 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 << instead of >> for input.

Using + or -- which are not input operators.

In C++, >> is used to get input from the user using std::cin.

3fill in blank

hard

Fix the error in the code to correctly read and print a number.

C++

#include <iostream>

int main() {
    int value;
    std::cout << "Enter value: ";
    std::cin [1] value;
    std::cout << "Value is " << value << 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 << instead of >> with std::cin.

Trying to use + or -- operators for input.

The input operator for std::cin is >>. Using << causes an error.

4fill in blank

hard

Fill both blanks to create a program that reads a number and prints its double.

C++

#include <iostream>

int main() {
    int num;
    std::cout << "Enter number: ";
    std::cin [1] num;
    std::cout << "Double is " << num [2] 2 << 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 << instead of >> for input.

Using + instead of * for doubling.

Use >> to read input and * to multiply the number by 2.

5fill in blank

hard

Fill all three blanks to read two numbers and print their sum.

C++

#include <iostream>

int main() {
    int a, b;
    std::cout << "Enter two numbers: ";
    std::cin [1] a >> b;
    int sum = a [2] b;
    std::cout [3] "Sum is: " << sum << std::endl;
    return 0;
}

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

A>>

B+

C<<

Attempts:

3 left

💡 Hint

Common Mistakes

Using << instead of >> for input.

Using - instead of + for addition.

Using >> instead of << for output.

Use >> to read both numbers, + to add them, and << to print the result.