std::islower
Defined in header <cctype> | | |
|---|---|---|
int islower( int ch ); | | |
根据当前C语言环境检查给定字符是否被归类为小写字符。在默认的“C”区域设置中，islower仅对小写字母%28返回非零值abcdefghijklmnopqrstuvwxyz29%。
如果islower返回一个非零值，则保证iscntrl，，，isdigit，，，ispunct，和isspace对于相同C语言环境中的相同字符，返回零。
如果ch不能表示为unsigned char不等于EOF...
参数
ch | - | character to classify |
|---|
返回值
如果字符是小写字母，则为非零值，否则为零.
例
二次
#include <iostream>
#include <cctype>
#include <clocale>
int main()
{
unsigned char c = '\xe5'; // letter å in ISO-8859-1
std::cout << "islower(\'\\xe5\', default C locale) returned "
<< std::boolalpha << (bool)std::islower(c) << '\n';
std::setlocale(LC_ALL, "en_GB.iso88591");
std::cout << "islower(\'\\xe5\', ISO-8859-1 locale) returned "
<< std::boolalpha << (bool)std::islower(c) << '\n';
}二次
产出：
二次
islower('\xe5', default C locale) returned false
islower('\xe5', ISO-8859-1 locale) returned true二次
另见
islower(std::locale) | checks if a character is classified as lowercase by a locale (function template) |
|---|---|
iswlower | checks if a wide character is lowercase (function) |
C.ISLER文件
ASCII values (hex) | 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. | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0 - 8 | 0x00-0x08 | control codes (NUL, etc.) | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
9 | 0x09 | tab (\t) | ≠0 | 0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
10 - 13 | 0x0A-0x0D | whitespaces (\n,\v,\f,\r) | ≠0 | 0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
14 - 31 | 0x0E-0x1F | control codes | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
32 | 0x20 | space | 0 | ≠0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
33 - 47 | 0x21-0x2F | !"#$%&'()*+,-./ | 0 | ≠0 | 0 | 0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 |
48 - 57 | 0x30-0x39 | 0123456789 | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | 0 | 0 | 0 | ≠0 | ≠0 |
58 - 64 | 0x3a-0x40 | :;<=>?@ | 0 | ≠0 | 0 | 0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 |
65 - 70 | 0x41-0x46 | ABCDEF | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | ≠0 | ≠0 | 0 | 0 | ≠0 |
71 - 90 | 0x47-0x5A | GHIJKLMNOPQRSTUVWXYZ | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | ≠0 | ≠0 | 0 | 0 | 0 |
91 - 96 | 0x5B-0x60 | []^_` | 0 | ≠0 | 0 | 0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | | ||||||||||||
97 -102 | 0x61-0x66 | abcdef | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | ≠0 | 0 | ≠0 | 0 | ≠0 |
103-122 | 0x67-0x7A | ghijklmnopqrstuvwxyz | 0 | ≠0 | 0 | 0 | ≠0 | 0 | ≠0 | ≠0 | 0 | ≠0 | 0 | 0 |
123-126 | 0x7B-0x7E | {|}~ | 0 | ≠0 | 0 | 0 | ≠0 | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 |
127 | 0x7F | backspace character (DEL) | ≠0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
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