isblank - cppreference.com (original) (raw)
| | | | | ---------------------- | | ----------- | | int isblank( int ch ); | | (since C99) |
Checks if the given character is a blank character in the current C locale. In the default C locale, only space (0x20) and horizontal tab (0x09) are classified as blank.
The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.
[edit] Parameters
| ch | - | character to classify |
|---|
[edit] Return value
Non-zero value if the character is a blank character, zero otherwise.
[edit] Example
#include <ctype.h> #include <limits.h> #include <stdio.h> int main(void) { for (int ndx = 0; ndx != UCHAR_MAX; ++ndx) if (isblank(ndx)) printf("0x%02x\n", ndx); }
Output:
[edit] References
C23 standard (ISO/IEC 9899:2024):
7.4.1.3 The isblank function (p: TBD)
C17 standard (ISO/IEC 9899:2018):
7.4.1.3 The isblank function (p: 145)
C11 standard (ISO/IEC 9899:2011):
7.4.1.3 The isblank function (p: 201)
C99 standard (ISO/IEC 9899:1999):
7.4.1.3 The isblank function (p: 182)
[edit] See also
| 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 | GHIJKLMNOPQRSTUVWXYZ | 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 | ghijklmnopqrstuvwxyz | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | ≠0 | 0 | ≠0 | 0 | 0 |
| 123–126 | \x7B–\x7E | \173–\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 |