std::islower

性病：：

Defined in header
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
9	0x09	tab (\t)	≠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
14 - 31	0x0E-0x1F	control codes	≠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
33 - 47	0x21-0x2F	!"#$%&'()*+,-./	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
58 - 64	0x3a-0x40	:;<=>?@	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
71 - 90	0x47-0x5A	GHIJKLMNOPQRSTUVWXYZ	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
103-122	0x67-0x7A	ghijklmnopqrstuvwxyz	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
127	0x7F	backspace character (DEL)	≠0	0	0	0	0	0	0	0	0	0	0

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