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 <stdio.h>

int main() {
    printf([1]);
    return 0;
}

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

A"Hello, World!\n"

B'Hello, World!'

Cprint("Hello, World!\n")

DHello, World!

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the double quotes around the string.

Using single quotes instead of double quotes.

The printf function requires a string in double quotes to print text.

2fill in blank

medium

Complete the code to read an integer from the user.

C

#include <stdio.h>

int main() {
    int number;
    scanf([1], &number);
    printf("You entered: %d\n", number);
    return 0;
}

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

A"%f"

B"%s"

Cnumber

D"%d"

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong format specifier like %f or %s.

Not using the & operator before the variable.

The scanf function uses %d to read an integer value.

3fill in blank

hard

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

C

#include <stdio.h>

int main() {
    float value;
    scanf([1], &value);
    printf("Value: %f\n", value);
    return 0;
}

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

A"%f"

Bvalue

C"%d"

D"%c"

Attempts:

3 left

💡 Hint

Common Mistakes

Using %d instead of %f for floats.

Not using & before the variable name.

Use %f in scanf to read a float value.

4fill in blank

hard

Fill both blanks to create a program that reads a character and prints it.

C

#include <stdio.h>

int main() {
    char ch;
    scanf([1], &ch);
    printf([2], ch);
    return 0;
}

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

A"%c"

B"%d"

C"You entered: %c\n"

D"%f"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong format specifiers like %d or %f.

Not matching format specifiers between scanf and printf.

Use %c in scanf to read a character and in printf to print it.

5fill in blank

hard

Fill all three blanks to create a program that reads two integers and prints their sum.

C

#include <stdio.h>

int main() {
    int a, b;
    scanf([1], &a);
    scanf([2], &b);
    printf([3], a + b);
    return 0;
}

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

A"%d"

B"%f"

C"Sum is: %d\n"

D"%c"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong format specifiers like %f or %c.

Forgetting to use & before variables in scanf.

Use %d to read integers and print their sum with a message.