std::islower
From cppreference.com
| Defined in header <cctype>
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| int islower( int ch ); |
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Checks if the given character is classified as a lowercase character according to the current C locale. In the default "C" locale, islower returns a nonzero value only for the lowercase letters (abcdefghijklmnopqrstuvwxyz).
If islower returns a nonzero value, it is guaranteed that iscntrl, isdigit, ispunct, and isspace return zero for the same character in the same C locale.
The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.
Contents |
[edit] Parameters
| ch | - | character to classify |
[edit] Return value
Non-zero value if the character is a lowercase letter, zero otherwise.
[edit] Example
Run this code
#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'; }
Output:
islower('\xe5', default C locale) returned false
islower('\xe5', ISO-8859-1 locale) returned true[edit] See also
| checks if a character is classified as lowercase by a locale (function template) | |
| checks if a wide character is lowercase (function) | |
| C documentation for islower
| |
| ASCII values (hex) |
characters |
islower |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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
|