std::tolower

 

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isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
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Defined in header <cctype>
int tolower( int ch );

Converts the given character to lowercase according to the character conversion rules defined by the currently installed C locale.

Parameters

ch

-

character to be converted

Return value

Lowercase version of ch or unmodified ch if no lowercase version is listed in the current C locale.

Example

run this code

#include <iostream>
#include <cctype>
#include <clocale>
 
int main()
{
    char c = '\xb4'; // the character Ž in ISO-8859-15
                     // but ´ (acute accent) in ISO-8859-1 
 
    std::setlocale(LC_ALL, "en_US.iso88591");
    std::cout << std::hex << std::showbase;
    std::cout << "in iso8859-1, tolower('0xb4') gives "
              << std::tolower(c) << '\n';
    std::setlocale(LC_ALL, "en_US.iso885915");
    std::cout << "in iso8859-15, tolower('0xb4') gives "
              << std::tolower(c) << '\n';
}

Output:

in iso8859-1, tolower('0xb4') gives 0xb4
in iso8859-15, tolower('0xb4') gives 0xb8

See also

toupper	converts a character to uppercase (function)
tolower(std::locale)	converts a character to lowercase using the ctype facet of a locale (function template)
towlower	converts a wide character to lowercase (function)