Using scanf for input - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read an integer from the user using scanf.

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"%d"

B"%f"

C"%c"

D"%s"

Attempts:

3 left

💡 Hint

Common Mistakes

Using %f or %c instead of %d for integer input.

Forgetting the quotes around the format specifier.

The format specifier %d is used to read an integer with scanf.

2fill in blank

medium

Complete the code to read a float value from the user using scanf.

C

#include <stdio.h>

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

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

A"%d"

B"%c"

C"%f"

D"%s"

Attempts:

3 left

💡 Hint

Common Mistakes

Using %d instead of %f for float input.

Forgetting the ampersand (&) before the variable.

The format specifier %f is used to read a float with scanf.

3fill in blank

hard

Fix the error in the scanf statement to correctly read a character.

C

#include <stdio.h>

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

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

A"%f"

B"%d"

C"%s"

D"%c"

Attempts:

3 left

💡 Hint

Common Mistakes

Using %d, %f or %s instead of %c for character input.

The format specifier %c is used to read a single character with scanf.

4fill in blank

hard

Complete the code to read a string safely using scanf.

C

#include <stdio.h>

int main() {
    char name[20];
    scanf([1], name);
    printf("Hello, %s!\n", name);
    return 0;
}

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

A"%19s"

B"%s"

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using %s without size limit, risking buffer overflow.

Using & before the array name when reading strings.

To safely read a string into an array, use %19s to limit input size. When reading strings into arrays, do not use the ampersand (&) because the array name is already a pointer.

5fill in blank

hard

Fill all three blanks to read two integers and one float from the user.

C

#include <stdio.h>

int main() {
    int a, b;
    float c;
    scanf("[1] [2] [3]", &a, &b, &c);
    printf("Integers: %d, %d and Float: %f\n", a, b, c);
    return 0;
}

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

A"%d %d %f"

B"%d %f %d"

C"%f"

D"%d"

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the order of format specifiers.

Using wrong format specifiers for variables.

The format string should match the variables: "%d %d %f" to read two integers and one float. Fill "%d" for the first two blanks and "%f" for the third.