The islower() function defined in the ctype.h header file. It helps to check the specified character is a lowercase alphabet (a-z) or not.
int islower( int argument ); #where argument will be a character
The islower() function takes a single parameter and is in the form of an integer and the return value should be an integer. When a character is passed it is converted into the integer value corresponding to its ASCII value.
Parameter | Description | Required / Optional |
---|---|---|
argument | The character to be checked | Required |
If the given character is a lowercase alphabet, islower() returns a non-zero integer else zero. When a lowercase alphabet character is passed we will get a different non-zero integer.
Input | Return Value |
---|---|
Zero | If the parameter isn't a lowercase alphabet |
Non zero number | If the parameter is a lowercase alphabet |
#include <stdio.h>
#include <ctype.h>
int main()
{
char ch;
ch='a';
printf("If %c is passed to islower(): %d", ch, islower(ch));
c='A';
printf("\nIf %c is passed to islower(): %d", ch, islower(ch));
return 0;
}
Output:
If a is passed to islower(): 2 If A is passed to is islower(): 0
#include <stdio.h>
#include <ctype.h>
int main()
{
char ch;
printf("Please enter a character: ");
scanf("%c", &ch);
if (islower(ch) == 0)
printf("The given %c is not a lowercase alphabet.", ch);
else
printf("The given %c is a lowercase alphabet.", ch);
return 0;
}
Output:
Please enter a character: h The given h is a lowercase alphabet.