In this source code example, we will see how to use the isblank() function in C programming with an example.

isblank() Function Overview

The isblank() function determines if the given character is a blank character, which includes space (' ') or a horizontal tab ('\t').

Key Points: 

- Requires the inclusion of the <ctype.h> header. 

- The function accepts an int (typically a character) as its argument. 

- It returns a non-zero value (true) if the character is blank; otherwise, it gives back 0 (false).

Source Code Example

#include <stdio.h> #include <ctype.h> int main() { char ch; printf("Enter a character: "); scanf("%c", &ch); if (isblank(ch)) printf("'%c' is a blank character.\n", ch); else printf("'%c' is not a blank character.\n", ch); return 0; } 

Output

Enter a character: ' ' is a blank character. 

Explanation

1. We begin by including the necessary header files: stdio.h for input/output functions and ctype.h for character functions.

2. Inside the main() function, we initialize a character variable named ch.

3. The user is prompted to enter a character.

4. The isblank() function is used to test if the provided character is a blank.

5. Depending on the function's result, the program prints a relevant message to the console.