Header files and include directive - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to include the standard input-output header file.

C

#include [1]

int main() {
    printf("Hello, world!\n");
    return 0;
}

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

A"stdio.h"

B<stdio.h>

C<stdlib.h>

D"stdlib.h"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes instead of angle brackets for standard headers.

Including the wrong header file like stdlib.h.

The standard input-output header file is included using angle brackets: #include .

2fill in blank

medium

Complete the code to include a user-defined header file named "myheader.h".

C

#include [1]

void greet();

int main() {
    greet();
    return 0;
}

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

A"myheader.h"

B<myheader.h>

C<stdio.h>

D"stdio.h"

Attempts:

3 left

💡 Hint

Common Mistakes

Using angle brackets for user-defined headers.

Including the wrong header file.

User-defined headers are included using double quotes: #include "myheader.h".

3fill in blank

hard

Fix the error in the include directive to correctly include the math header.

C

#include [1]

int main() {
    double result = sqrt(16.0);
    return 0;
}

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

A<math>

B"math.h"

C<math.h>

D"math"

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the .h extension.

Using quotes instead of angle brackets.

The math header is a standard library header and must be included with angle brackets: #include .

4fill in blank

hard

Fill both blanks to include the header and declare a function prototype.

C

#include [1]

[2] greet();

int main() {
    greet();
    return 0;
}

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

A"myheader.h"

Bvoid

Cint

D<stdio.h>

Attempts:

3 left

💡 Hint

Common Mistakes

Using angle brackets for user headers.

Omitting the return type in function prototype.

User header included with quotes and function prototype declared with return type void.

5fill in blank

hard

Fill all three blanks to create a header guard in a header file.

C

#ifndef [1]
#define [2]

void greet();

#endif // [3]

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

AMYHEADER_H

DGREET_H

Attempts:

3 left

💡 Hint

Common Mistakes

Using different macro names in the guard.

Omitting the header guard entirely.

Header guards use the same unique macro name to prevent multiple inclusions.