isspace

< c‎ | string‎ | byte
 
C
 
Strings library
 
Null-terminated byte strings
Functions
Character manipulation
Conversions to numeric formats
String manipulation
(C11)
(C11)
(C11)
(C11)
String examination
Memory manipulation
(C11)
(C11)
(C11)
Miscellaneous
(C11)(C11)
 
Defined in header <ctype.h>
int isspace( int ch );

Checks if the given character is a whitespace character, i.e. either space (0x20), form feed (0x0c), line feed (0x0a), carriage return (0x0d), horizontal tab (0x09) or vertical tab (0x0b).

The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.

Parameters

ch - character to classify

Return value

Non-zero value if the character is a whitespace character, zero otherwise.

Example

Run this code
#include <stdio.h>
#include <ctype.h>
#include <limits.h>
 
int main(void)
{
    for (int ndx=0; ndx<=UCHAR_MAX; ndx++)
        if (isspace(ndx)) printf("0x%02x\n", ndx);
}

Output: 

0x09
0x0a
0x0b
0x0c
0x0d
0x20

References

  • C11 standard (ISO/IEC 9899:2011):
  • 7.4.1.10 The isspace function (p: 202-203)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.4.1.10 The isspace function (p: 183-184)
  • C89/C90 standard (ISO/IEC 9899:1990):
  • 4.3.1.9 The isspace function

See also

(C95)
 checks if a wide character is a space character
(function)
ASCII values characters

iscntrl
iswcntrl

isprint
iswprint

isspace
iswspace

isblank
iswblank

isgraph
iswgraph

ispunct
iswpunct

isalnum
iswalnum

isalpha
iswalpha

isupper
iswupper

islower
iswlower

isdigit
iswdigit

isxdigit
iswxdigit

decimal hexadecimal octal
0–8 \x0–\x8 \0–\10 control codes (NUL, etc.) ≠0 0 0 0 0 0 0 0 0 0 0 0
9 \x9 \11 tab (\t) ≠0 0 ≠0 ≠0 0 0 0 0 0 0 0 0
10–13 \xA–\xD \12–\15 whitespaces (\n, \v, \f, \r) ≠0 0 ≠0 0 0 0 0 0 0 0 0 0
14–31 \xE–\x1F \16–\37 control codes ≠0 0 0 0 0 0 0 0 0 0 0 0
32 \x20 \40 space 0 ≠0 ≠0 ≠0 0 0 0 0 0 0 0 0
33–47 \x21–\x2F \41–\57 !"#$%&'()*+,-./ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
48–57 \x30–\x39 \60–\71 0123456789 0 ≠0 0 0 ≠0 0 ≠0 0 0 0 ≠0 ≠0
58–64 \x3A–\x40 \72–\100 :;<=>?@ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
65–70 \x41–\x46 \101–\106 ABCDEF 0 ≠0 0 0 ≠0 0 ≠0 ≠0 ≠0 0 0 ≠0
71–90 \x47–\x5A \107–\132 GHIJKLMNOP
QRSTUVWXYZ 		0 ≠0 0 0 ≠0 0 ≠0 ≠0 ≠0 0 0 0
91–96 \x5B–\x60 \133–\140 [\]^_` 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
97–102 \x61–\x66 \141–\146 abcdef 0 ≠0 0 0 ≠0 0 ≠0 ≠0 0 ≠0 0 ≠0
103–122 \x67–\x7A \147–\172 ghijklmnop
qrstuvwxyz 		0 ≠0 0 0 ≠0 0 ≠0 ≠0 0 ≠0 0 0
123–126 \x7B–\x7E \172–\176 {|}~ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
127 \x7F \177 backspace character (DEL) ≠0 0 0 0 0 0 0 0 0 0 0 0