C Program to Check the Character is Lowercase or Uppercase Alphabet

Write a C Program to Check the Character is Lowercase or Uppercase Alphabet using built-in functions and ASCII codes.

C Program to Check the Character is Lowercase or Uppercase Alphabet

This C program allows the user to enter any character and check whether the character is an uppercase alphabet or not using built-in functions isupper, and islower

TIP: In C Programming, there are built-in functions in <ctype.h> header file called isupper, and islower. You can use these functions to check whether the character is a lowercase alphabet or uppercase alphabet.

/* C Program to check the Character is Lowercase or Uppercase Alphabet */

#include<stdio.h>
#include<ctype.h>

int main()
{
	char Ch;
 
  	printf("\n Please Enter any alphabet  :  ");
  	scanf("%c", &Ch);
 
  	if ( islower(Ch) )
   	{  
    	printf ("\n Entered character is a Lowercase Alphabet");
   	}
    else if ( isupper(Ch) )
   	{  
    	printf ("\n Entered character is an Uppercase Alphabet");
   	}
  	else
   	{
    	printf("\n Entered character is Not an Alphabet");
   	}
	return 0;   
}

OUTPUT 1

OUTPUT 2

3rd OUTPUT

Program to Check the Character is Lowercase or Uppercase Alphabet Example 2

In this program, we are not using isupper or islower function. Instead of them, we are directly placing alphabets inside the If Statement.

/* C Program to check the Character is Lowercase or Uppercase Alphabet */

#include<stdio.h>

int main()
{
 	char Ch;
 
  	printf("\n Please Enter any alphabet\n");
  	scanf("%c", &Ch);
 
  	if (Ch >= 'a' && Ch <= 'z')
   	{  
    	printf ( "\n Entered character is a Lowercase Alphabet") ;
   	}
   	else if (Ch >= 'A' && Ch <= 'Z')
  	{  
    	printf ( "\n Entered character is an Uppercase Alphabet") ;
   	}
  	else
   	{
    	printf("\n Entered character is Not an Alphabet");
   	} 
	return 0;    
}

OUTPUT

Let us check with a false value

Program to Check the Character is Lowercase or Uppercase Alphabet Example 3

In this program we are using the ASCII codes to check whether the Character is an Uppercase alphabet or lowercase alphabet. I suggest you to refer ASCII Table article to understand the codes.

/* C Program to check the Character is Lowercase or Uppercase Alphabet */

#include<stdio.h>

int main()
{
 	char Ch;
 
  	printf("\n Please Enter any alphabet\n");
  	scanf("%c", &Ch);
 
  	if (Ch >= 65 && Ch <= 90)
   	{  
    	printf ( "\n Entered character is an Uppercase Alphabet") ;
   	}
   	else if (Ch >= 97 && Ch <= 122)
  	{  
    	printf ( "\n Entered character is a Lowercase Alphabet") ;
   	}
  	else
   	{
    	printf("\n Entered character is Not an Alphabet");
   	} 
	return 0;    
}

OUTPUT