C Program to Check Uppercase Lowercase Number and Special Character

C program to check uppercase lowercase number and special characters.

In this article, you will learn how to check if the given input character is a lowercase letter or uppercase letter or a number or a special character.

To solve this we'll use conditional statements and functions, we can solve this problem in three approaches 1. if-else statement, 2. nested if-else statement, and 3. using functions.

Example-1

Example-2

Example-3

You should know about the following topics in C programming to understand this program:

• C If-else statement
• C Nested if..if-else statement
• C Functions

1 - Check Uppercase Lowercase Number and Special Characters using If-Else

// C Program to Check Uppercase Lowercase Number and Special Character using If-Else
#include <stdio.h>

// It's the main function of the program
int main() {
    char char_str;

    // Step-1 Take input from the user
    printf("Enter a character: ");
    scanf("%c", &char_str);

    // Step-2 Check the character & print final output of the program
    printf("Output :: ");

    // Step-2.1 If the character is lowercase
    if (char_str >= 'a' && char_str <= 'z') {
        printf("LOWER CASE LETTER\n");
    }

    // Step-2.2 If the character is uppercase
    else if (char_str >= 'A' && char_str <= 'Z') {
        printf("UPPER CASE LETTER\n");
    }

    // Step-2.3 If the character is a number
    else if (char_str >= '0' && char_str <= '9') {
        printf("NUMBER\n");
    }

    // Step-2.4 If the above conditions are false then the character is a special character
    else {
        printf("SPECIAL CHARACTER\n");
    }
    return 0;
}

Run

Output

2 - Check Uppercase Lowercase Number and Special Characters using Nested If-Else

// C Program to Check Uppercase Lowercase Number and Special Character using Nested If-Else
#include <stdio.h>

// It's the main function of the program
int main() {
    char char_str;

    // Step-1 Take input from the user
    printf("Enter a character: ");
    scanf("%c", &char_str);

    // Step-2 Check the character & print final output of the program
    printf("Output :: ");

    // Step-2.1 If the character is lowercase
    if (char_str >= 'a' && char_str <= 'z') {
        printf("LOWER CASE LETTER\n");
    }
    else {
        // Step-2.2 If the character is uppercase
        if (char_str >= 'A' && char_str <= 'Z') {
            printf("UPPER CASE LETTER\n");
        }
        else {
            // Step-2.3 If the character is a number
            if (char_str >= '0' && char_str <= '9') {
                printf("NUMBER\n");
            }
            
            // Step-2.4 If the above conditions are false then the character is a special character
            else {
                printf("SPECIAL CHARACTER\n");
            }
        }
    }
    return 0;
}

Run

Output

3 - Check Uppercase Lowercase Number and Special Characters using Function

// C Program to Check Uppercase Lowercase Number and Special Character using Function
#include <stdio.h>

// Function: To check the lowercase letter
int lower_case(char str) {
    if (str >= 'a' && str <= 'z') {
        printf("LOWER CASE LETTER\n");
        return 1;
    }
    return 0;
}

// Function: To check the uppercase letter
int upper_case(char str) {
    if (str >= 'A' && str <= 'Z') {
        printf("UPPER CASE LETTER\n");
        return 1;
    }
    return 0;
}

// Function: To check the number
int number(char str) {
    if (str >= '0' && str <= '9') {
        printf("NUMBER\n");
        return 1;
    }
    return 0;
}

// It's the main function of the program
int main() {
    char char_str;

    // Step-1 Take input from the user
    printf("Enter a character: ");
    scanf("%c", &char_str);

    // Step-2 Check the character & print final output of the program
    printf("Output :: ");

    // Step-3 If the character is lowercase or uppercase or number or special character
    if (lower_case(char_str) || upper_case(char_str) || number(char_str)) { }
    else {
        printf("SPECIAL CHARACTER\n");
    }

    return 0;
}

Run

Output