< cpp‎ | locale
Localizations library
Locales and facets
Facet category base classes
ctype facets
numeric facets
collate facets
time facets
monetary facets
messages facets
Character classification and conversion
Character classification
Code conversion facets
C locale
Text encoding identifications
Defined in header <locale>
template< class CharT >
bool islower( CharT ch, const locale& loc );

Checks if the given character is classified as a lowercase alphabetic character by the given locale's std::ctype facet.


[edit] Parameters

ch - character
loc - locale

[edit] Return value

Returns true if the character is classified as lowercase, false otherwise.

[edit] Possible implementation

template<class CharT>
bool islower(CharT ch, const std::locale& loc)
    return std::use_facet<std::ctype<CharT>>(loc).is(std::ctype_base::lower, ch);

[edit] Example

Demonstrates the use of islower() with different locales (OS-specific).

#include <iostream>
#include <locale>
int main()
    const wchar_t c = L'\u03c0'; // GREEK SMALL LETTER PI
    std::locale loc1("C");
    std::cout << std::boolalpha
              << "islower('π', C locale) returned "
              << std::islower(c, loc1) << '\n'
              << "isupper('π', C locale) returned "
              << std::isupper(c, loc1) << '\n';
    std::locale loc2("en_US.UTF8");
    std::cout << "islower('π', Unicode locale) returned "
              << std::islower(c, loc2) << '\n'
              << "isupper('π', Unicode locale) returned "
              << std::isupper(c, loc2) << '\n';

Possible output:

islower('π', C locale) returned false
isupper('π', C locale) returned false
islower('π', Unicode locale) returned true
isupper('π', Unicode locale) returned false

[edit] See also

checks if a character is lowercase
(function) [edit]
checks if a wide character is lowercase
(function) [edit]