islower, iswlower, _ismbclower

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Header File

ctype.h, mbstring.h

Category

Classification Routines

Prototype

int islower(int c);

int iswlower(wint_t c);

int _ismbclower(unsigned int c);

Description

Tests for lowercase character.

islower is a macro that classifies ASCII-coded integer values by table lookup. The macro is affected by the current locale's LC_CTYPE category. For the default C locale, c is a lowercase letter (a to z).

You can make this macro available as a function by undefining (#undef) it.

Return Value

islower returns nonzero if c is a lowercase letter.

Example

#include <stdio.h>
#include <ctype.h>
int main(void)
{
  char c = 'C';
  if (islower(c))
    printf("%c is a lowercase character\n",c);
  else
    printf("%c is not a lowercase character\n",c);
  return 0;
}

Portability

	POSIX	Win32	ANSI C	ANSI C++
islower	+	+	+	+
_ismbclower		+
iswlower		+	+	+