C program to check whether a character is alphabet, digit or special character

Write a C program to input a character from user and check whether given character is alphabet, digit or special character using if else. How to check if a character is alphabet, digits or any other special character using if else in C programming. Logic to check alphabet, digit or special character in C programming.

Example
Input

Input any character: 3

Output

3 is digit

Required knowledge

Basic C programming, Relational operators, Logical operators, If else

Logic to check alphabet, digit or special character

  • A character is alphabet if it in between a-z or A-Z.
  • A character is digit if it is in between 0-9.
  • A character is special symbol character if it neither alphabet nor digit.

Step by step descriptive logic to check alphabet, digit or special character.

  1. Input a character from user. Store it in some variable say ch.
  2. First check if character is alphabet or not. A character is alphabet if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')).
  3. Next, check condition for digits. A character is digit if(ch >= '0' && ch <= '9').
  4. Finally, if a character is neither alphabet nor digit, then character is a special character.

Let us implement the above logic in a C program.

Program to check alphabet, digit or special character

/**
 * C program to check alphabet, digit or special character
 */

#include <stdio.h>

int main()
{
    char ch;

    /* Input character from user */
    printf("Enter any character: ");
    scanf("%c", &ch);


    /* Alphabet check */
    if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
    {
        printf("'%c' is alphabet.", ch);
    }
    else if(ch >= '0' && ch <= '9')
    {
        printf("'%c' is digit.", ch);
    }
    else 
    {
        printf("'%c' is special character.", ch);
    }

    return 0;
}

Note: You can also use ASCII character codes for checking alphabets, digits or special characters as shown in below program.

Program to check alphabet, digit or special character using ASCII value

/**
 * C program to check alphabet, digit or special character using ASCII value
 */

#include <stdio.h>

int main()
{
    char ch;

    /* Input a character from user */
    printf("Enter any character: ");
    scanf("%c", &ch);


    if((ch >= 97 && ch <= 122) || (ch >= 65 && ch <= 90))
    {
        printf("'%c' is alphabet.", ch);
    }
    else if(ch >= 48 && ch <= 57)
    {
        printf("'%c' is digit.", ch);
    }
    else
    {
        printf("'%c' is special character.", ch);
    }

    return 0;
}

Output

Enter any character: a
'a' is alphabet.

Happy coding 😉

About Pankaj

Pankaj Prakash is the founder, editor and blogger at Codeforwin. He loves to learn new techs and write programming articles especially for beginners. He works at Vasudhaika Software Sols as a Software Design Engineer and manages Codeforwin. In short Pankaj is Web developer, Blogger, Learner, Tech and Music lover.

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