std::islower(std::locale)

 

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Locales and facets   Locales has_facet use_facet locale Facet category base classes ctype_base codecvt_base messages_base time_base money_base ctype facets ctype ctype<char> ctype_byname codecvt codecvt_byname numeric facets num_get num_put numpunct numpunct_byname collate facets collate collate_byname time facets time_get time_put time_get_byname time_put_byname

monetary facets money_get money_put moneypunct moneypunct_byname messages facets messages messages_byname Character classification and conversion Character classification isspace    iscntrl isupper islower    isalpha ispunct isdigit    isxdigit isalnum isblank (C++11) isprint isgraph Character conversions toupper    tolower String and stream conversions wstring_convert (C++11/17/26*) wbuffer_convert (C++11/17/26*) Unicode conversion facets codecvt_utf8 (C++11/17/26*) codecvt_utf16 (C++11/17/26*) codecvt_utf8_utf16 (C++11/17/26*) codecvt_mode (C++11/17/26*) C library locales LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME    setlocale localeconv lconv

 

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.

Parameters

ch	-	character
loc	-	locale

Return value

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

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); }

Example

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

Run this code

#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

See also

islower	checks if a character is lowercase (function)
iswlower	checks if a wide character is lowercase (function)