The C islower function is one of the Standard Library Functions available in this C programming language. This function used to check the given character is a lowercase alphabet or not. Let us see how to use islower in C Programming language with example.
C islower Function syntax
The C Programming islower is a built-in function present in the header file used to check whether the character is a lowercase alphabet or not. The Syntax of the C islower function is.
islower(char)
The above islower function will accept a single character as the parameter and check whether the given character is in lowercase or not. The islower function will return an integer value as output.
- If the character inside the islower function is in lowercase, then it will return non zero value
- If the character inside the islower function is not in lowercase, it will return 0
islower in C Programming Example
The C islower method used to find whether the given character is a lowercase character or not.
This C program allows the user to enter any character, and check whether the character is between a to z using the islower function.
//Example for islower in C Programming #include <stdio.h> #include <ctype.h> int main() { char ch; printf("Please Enter Any Lowercase Character: \n"); scanf("%c", &ch); if(islower(ch)) { printf("\n You have entered a Lowercase Character"); } else { printf("\n %c is not a Lowercase Alphabet", ch); printf("\n I request you to enter Valid Lowercase Character"); } }
OUTPUT
Let me enter the Uppercase letter
ANALYSIS
First, we declared a character variable called ch
char ch;
The following statement will ask the user to enter any character. And then we are using the C Programming scanf to assign the user entered a character to ch variable
printf("Please Enter Any Lowercase Character: \n"); scanf("%c", &ch);
In this next line, we added the If Statement to check whether the character is between ‘a’ and ‘z’ or not using C islower function. If the condition is True, then the following statement will print
printf("\n You have entered a Lowercase Character");
If the above condition is FALSE, the given character is not a lowercase Alphabet. So, it will print below statements
printf("\n %c is not a Lowercase Alphabet", ch); printf("\n I request you to enter Valid Lowercase Character");
The above code will definitely check whether the given character is a lowercase character or not, but what if we enter the numeric value
TIP: Please refer C Program to check whether the Character is Lowercase or Not article. It helps you know how to check whether the character is lowercase or not without using the islower function.