function template
<locale>

std::islower

template <class charT>
  bool islower (charT c, const locale& loc);
Check if character is a lowercase letter using locale
Checks whether c is a lowercase letter using the ctype facet of locale loc, returning the same as if ctype::is is called as:

 
 
use_facet < ctype<charT> > (loc).is (ctype_base::lower, c)


This function template overloads the C function islower (defined in <cctype>).

Parameters

c
Character to be checked.
loc
Locale to be used. It shall have a ctype facet.

The template argument charT is the character type.

Return Value

true if indeed c is a lowercase letter.
false otherwise.

Example

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// islower example (C++)
#include <iostream>       // std::cout
#include <string>         // std::string
#include <locale>         // std::locale, std::islower, std::toupper

int main ()
{
  std::locale loc;
  std::string str="Test String.\n";
  char c;
  for (std::string::size_type i=0; i<str.length(); ++i)
  {
    c=str[i];
    if (std::islower(c,loc)) c=std::toupper(c,loc);
    std::cout << c;
  }
  return 0;
}


Output:
TEST STRING.

Data races

Both loc and its ctype facet are accessed.

Exception safety

Strong guarantee: if an exception is thrown, there are no effects.

See also

ctype
Character type facet (class template )
islower (cctype)
Check if character is lowercase letter (function )
isupper
Check if character is an uppercase letter using locale (function template )
isalpha
Check if character is alphabetic using locale (function template )
toupper
Convert lowercase letter to uppercase using locale (function template )
tolower
Convert uppercase letter to lowercase using locale (function template )

C++