isspace in C Programming

The C isspace function is one of the Standard Library Functions available in C programming, which is useful to check the given character is a space or not. The basic syntax of the isspace in C Programming language is as shown below.

The below C isspace function function will accept a single character as the parameter, and find whether the given character is a space or not.

isspace(char)

isspace in C Programming Example 1

The isspace function used to find whether the given character is a space character or not.

//Example for isspace in C Programming
#include <stdio.h>
#include <ctype.h>

int main()
{
    char ch = ' ';
    
    if(isspace(ch))
    {
        printf("The Character ch is a Space Character \n");
    }
    else
    {
        printf("The Character ch is Not a Space Character \n");
    }
    return 0;
}

The Character ch is a Space Character 

isspace in C Programming Example 2

This C program allows the user to enter any character, and check whether the character is space or not using the isspace function.

//Example for isspace in C Programming
#include <stdio.h>
#include <ctype.h>

int main()
{
    char ch;
    printf("Please Enter Any Valid Character : \n");
    scanf("%c", &ch);

    if(isspace(ch))
    {
      printf("\n You have entered a Space Character");         
    }
    else
    {
      printf("\n %c is not a Space Character", ch);
      printf("\n I request you to enter Space Character");	
    }
}

Let me enter the Uppercase letter

Please Enter Any Valid Character : 
T

 T is not a Space Character
 I request you to enter Space Character

First, we declared a character variable called ch.

char ch;

The first C Programming statement will ask the user to enter any character. And then we are using the scanf to assign the user entered character to ch variable

printf("Please Enter Any Valid Character : \n");
scanf("%c", &ch);

Next, we used the If Statement to check whether the character is space, or not using isspace function. If the condition is True, then the following statement will be printed

printf("\n You have entered a Space Character");

If the above condition is FALSE, then the given character is not space. So, it will print below statements

printf("\n %c is not a Space Character", ch);
printf("\n I request you to enter Space Character");

Without using isspace Example

This C program allows the user to enter any character, and check whether the character is space or not using the ASCII table. Here we don’t use the built-in function isspace.

//Example for isspace in C Programming
#include <stdio.h>
#include <ctype.h>

int main()
{
    char ch;
    printf("Please Enter Any Valid Character : \n");
    scanf("%c", &ch);

    if(ch == 32)
    {
      printf("\n You have entered a Space Character");         
    }
    else
    {
      printf("\n %c is not a Space Character", ch);
      printf("\n I request you to enter Space Character");	
    }
}

Please Enter Any Valid Character : 
 

 You have entered a Space Character

Since 32 is the ASCII value for space, we replaced the C isspace function with 32. I suggest you cross-check the ASCII table. Let me try another value

Please Enter Any Valid Character : 
m

 m is not a Space Character
 I request you to enter Space Character