isblank Function

Test for a space or tab character.

Include

<ctype.h>

Prototype

int isblank (int c);

Argument

c
The character to test.

Return Value

Returns a non-zero integer value if the character is a space or tab character; otherwise, returns zero.

Remarks

A character is considered to be a white-space character if it is one of the following: space (' ') or horizontal tab ('\t').

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

#include <ctype.h>
#include <stdio.h>

int main(void)
{
  int ch;

  ch = '&';
  if (isblank(ch))
    printf("& is a white-space character\n");
  else
    printf("& is NOT a white-space character\n");

  ch = '\t';
  if (isblank(ch))
    printf("A tab is a white-space character\n");
  else
    printf("A tab is NOT a white-space character\n");
}

Example Output

& is NOT a white-space character
A tab is a white-space character