Write a C Program to check whether the Character is Alphabet or Digit by using the Built-in function isalpha, isdigit, and also not using any built-in function.
C Program to check whether the Character is Alphabet or Digit
This program allows the user to enter one character. Then it will check whether the user-specified character is an Alphabet or a digit.
#include <stdio.h> int main() { char ch; printf(" Please Enter any character : "); scanf("%c", &ch); if( (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') ) { printf("\n %c is an Alphabet", ch); } else if (ch >= '0' && ch <= '9') { printf("\n %c is a Digit", ch); } else printf("\n %c is not an Alphabet, or a Digit", ch); return 0; }

Let us check whether 7 is an Alphabet or Digit
Please Enter any character : 7
7 is a Digit
Let us check whether $ is an Alphabet or not (which is not TRUE)
Please Enter any character : $
$ is not an Alphabet, or a Digit
Check whether the Character is Alphabet or Digit 2
In this program, we are using the ASCII values to check whether the input character is Alphabet or Digit. I suggest you refer to the ASCII Table to understand the values of each character in C Programming.
#include <stdio.h> int main() { char ch; printf(" Please Enter any character : "); scanf("%c", &ch); if (ch >= 48 && ch <= 57) { printf("\n %c is a Digit", ch); } else if ( (ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122) ) { printf("\n %c is an Alphabet", ch); } else printf("\n %c is not an Alphabet, or a Digit", ch); return 0; }
Please Enter any character : 7
7 is a Digit
Let us check whether # is an Alphabet or not (Not TRUE)
Please Enter any character : #
# is not an Alphabet, or a Digit
Let us check whether g is an Alphabet or not (TRUE)
Please Enter any character : g
g is an Alphabet
In this program, we are using the built-in functions isalpha and isdigit to check whether the input character is Alphabet or Digit
#include <stdio.h> #include<ctype.h> int main() { char ch; printf(" Please Enter any character : "); scanf("%c", &ch); if (isdigit(ch)) { printf("\n %c is a Digit", ch); } else if ( isalpha(ch) ) { printf("\n %c is an Alphabet", ch); } else printf("\n %c is not an Alphabet, or a Digit", ch); return 0; }
Please Enter any character : @
@ is not an Alphabet, or a Digit