Write a c++ program to check whether a character is uppercase or lowercase alphabet.

Given a character, the task is to check whether the given character is in upper case, lower case, or non-alphabetic character
Examples:

Input: ch = 'A' Output: A is an UpperCase character Input: ch = 'a' Output: a is an LowerCase character Input: ch = '0' Output: 0 is not an aplhabetic character

Approach: The key to solving this problem lies in the ASCII value of a character. It is the simplest way to find out about a character. This problem is solved with the help of the following detail:

#include<bits/stdc++.h>
using namespace std;
void check(char ch)
{
    if (ch >= 'A' && ch <= 'Z')
        cout<< ch << " is an UpperCase character\n";
    else if (ch >= 'a' && ch <= 'z')
    cout<< ch << " is an LowerCase character\n";
    else
        cout<< ch << " is not an aplhabetic character\n";
}
int main()
{
    char ch;
    ch = 'A';
    check(ch);
    ch = 'a';
    check(ch);
    ch = '0';
    check(ch);
    return 0;
}

#include <stdio.h>
void check(char ch)
{
    if (ch >= 'A' && ch <= 'Z')
        printf("\n%c is an UpperCase character",
               ch);
    else if (ch >= 'a' && ch <= 'z')
        printf("\n%c is an LowerCase character",
               ch);
    else
        printf("\n%c is not an aplhabetic character",
               ch);
}
int main()
{



    char ch;
    ch = 'A';
    check(ch);
    ch = 'a';
    check(ch);
    ch = '0';
    check(ch);
    return 0;
}

class GFG
{
    static void check(char ch)
    {
        if (ch >= 'A' && ch <= 'Z')
            System.out.println("\n" + ch +
                    " is an UpperCase character");
        else if (ch >= 'a' && ch <= 'z')
            System.out.println("\n" + ch +
                    " is an LowerCase character" );
        else
            System.out.println("\n" + ch +
                    " is not an aplhabetic character" );
    }
    public static void main(String []args)
    {
        char ch;
        ch = 'A';
        check(ch);
        ch = 'a';
        check(ch);
        ch = '0';
        check(ch);
    }
}

def check(ch):
    if (ch >= 'A' and ch <= 'Z'):
        print(ch,"is an UpperCase character");
    elif (ch >= 'a' and ch <= 'z'):
        print(ch,"is an LowerCase character");
    else:
        print(ch,"is not an aplhabetic character");
ch = 'A';
check(ch);
ch = 'a';
check(ch);
ch = '0';
check(ch);

using System;
class GFG
{
    static void check(char ch)
    {
        if (ch >= 'A' && ch <= 'Z')
            Console.WriteLine("\n" + ch +
                    " is an UpperCase character");
        else if (ch >= 'a' && ch <= 'z')
            Console.WriteLine("\n" + ch +
                    " is an LowerCase character" );
        else
            Console.WriteLine("\n" + ch +
                    " is not an aplhabetic character" );
    }
    public static void Main(String []args)
    {
        char ch;
        ch = 'A';
        check(ch);
        ch = 'a';
        check(ch);
        ch = '0';
        check(ch);
    }
}

<?php
function check($ch)
{
    if ($ch >= 'A' && $ch <= 'Z')
        print($ch . " is an UpperCase character\n");
    else if ($ch >= 'a' && $ch <= 'z')
        print($ch . " is an LowerCase character\n");
    else
        print($ch . " is not an aplhabetic " .
                               "character\n");
}
$ch = 'A';
check($ch);
$ch = 'a';
check($ch);
$ch = '0';
check($ch);
?>

<script>
      function check(ch) {
        if (ch >= "A" && ch <= "Z")
          document.write(ch +
          " is an UpperCase character <br>");
        else if (ch >= "a" && ch <= "z")
          document.write(ch +
          " is an LowerCase character <br>");
        else document.write(ch +
        " is not an aplhabetic character <br>");
      }
      var ch;
      ch = "A";
      check(ch);
      ch = "a";
      check(ch);



      ch = "0";
      check(ch);
</script>

OutputA is an UpperCase character a is an LowerCase character 0 is not an aplhabetic character

Time Complexity: O(1) as it is doing constant operations
Auxiliary Space: O(1)

islower() – check whether a character is lowercase.

isupper() – check whether a character is uppercase.

Below is the implementation of the above approach.

#include <bits/stdc++.h>
using namespace std;
void check(char ch)
{
    if (isupper(ch))
        cout << ch << " is an UpperCase character\n";
    else if (islower(ch))
        cout << ch << " is an LowerCase character\n";
    else
        cout << ch << " is not an aplhabetic character\n";
}
int main()
{
    char ch;
    ch = 'A';
    check(ch);
    ch = 'a';
    check(ch);
    ch = '0';
    check(ch);
    return 0;
}