islower

Synopsis

#include <ctype.h>

int islower(int c);

Status

Implemented

Conformance

IEEE Std 1003.1-2017

Description

The islower() function shall test whether c is a character of class lower in the current locale.

The c argument is an int, the value of which the application shall ensure is a character representable as an unsigned char or equal to the value of the macro EOF. If the argument has any other value, the behavior is undefined.

Return value

The islower() function shall return non-zero if c is a lowercase letter, otherwise shall return 0.

Errors

No errors are defined.

Tests

Tested

Known bugs

None