It is a standard library function of C language.
This function is used to check if entered wide character is lower case or not. a main difference between iswlower and islower is that islower returns nonzero value only if entered character is in the set (a to z), but an additional concept in iswlower is, it returns non zero value only when entered character is in between(a to z) and it is a wide character[1] It comes under standard library function wctype.h.[2]

Syntax

# include <wctype.c>
int iswlower (wint_t wc);


The iswlower() function is designed to return non-zero(which is considered as true value) value if wc is a wide character and belongs to (a to z) And again it returns zero representing false value if it does not satisfy above condition [3]

Parameters required
a wide character like wc in above example
Example

# include<stdio.h>
#include<ctype.h>
int main ()
{
	char a;
	int b;
	scanf ("%c", &a);
	b = iswlower(a);
return 0;
}


The above code shows us how this function can be used.Thus if entered value is wide character and of lower case and do not contain any symbols, it returns a non zero value.Else it returns a zero.
References