Usage and example of C library function isspace()

C Standard Library <ctype.h>

The ispace() function checks whether the character is a whitespace character.

If the parameter (character) passed to the ispace() function is a whitespace character, it will return a non-zero integer. If not, it returns 0.

Function prototype of ispace()

int ispace(int argument);

When a character is passed as an argument, the corresponding ASCII value (integer) of the character is passed, rather than passing the character itself.

The ispace() function inctype.hDefined in header files.

The list of all whitespace characters in C language programming is:

Example #1Check for space character

#include <stdio.h>
#include <ctype.h>
int main()
{
　　　　char c;
　　　　int result;
　　　　printf("Enter a character: ");
　　　　scanf("%c", &c);
　　　　
　　　　result = isspace(c);
　　　　if (result == 0)
　　　　{
　　　　　　　　printf("Not a space character.");
　　　　}
　　　　else
　　　　{
　　　　　　　　printf("Space character.");
　　　　}
　　　　return 0;
}

Output Result

Enter a character:　5
Not a space character.

C Standard Library <ctype.h>