PROGRAM TO CHECK ALPHABET OR NOT :

#include <stdio.h>
int main()
{
    char c;
   
    printf("Enter a character: ");
    scanf("%c",&c);
   
    if( (c>='a' && c<='z') || (c>='A' && c<='Z'))
        printf("%c is an alphabet.",c);
    else
        printf("%c is not an alphabet.",c);
    return 0;
}

OUTPUT :

Enter a character: apurba

a is an alphabet.

Enter a character : 137ffsd

1 is not an alphabet.

Enter a character : coderscrazy

c is an alphabet.