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

In the default"C" locale, the following uppercase lettersABCDEFGHIJKLMNOPQRSTUVWXYZ are replaced with respective lowercase lettersabcdefghijklmnopqrstuvwxyz.

[edit]Parameters

[edit]Return value

Lowercase version ofch or unmodifiedch if no lowercase version is listed in the current C locale.

[edit]Notes

Like all other functions from<cctype>, the behavior ofstd::tolower is undefined if the argument's value is neither representable asunsignedchar nor equal toEOF. To use these functions safely with plainchars (orsignedchars), the argument should first be converted tounsignedchar:

char my_tolower(char ch){returnstatic_cast<char>(std::tolower(static_cast<unsignedchar>(ch)));}

Similarly, they should not be directly used with standard algorithms when the iterator's value type ischar orsignedchar. Instead, convert the value tounsignedchar first:

std::string str_tolower(std::string s){std::transform(s.begin(), s.end(), s.begin(),// static_cast<int(*)(int)>(std::tolower)         // wrong// [](int c){ return std::tolower(c); }           // wrong// [](char c){ return std::tolower(c); }          // wrong[](unsignedchar c){return std::tolower(c);}// correct);return s;}

[edit]Example

#include <cctype>#include <clocale>#include <iostream> int main(){unsignedchar 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';}

in iso8859-1, tolower('0xb4') gives 0xb4in iso8859-15, tolower('0xb4') gives 0xb8

[edit]See also

[edit]External links

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