Java program to demonstrate how to check if a character is an Uppercase or Lowercase letter.
package com.hubberspot.example;
public class IsUpperLowerCaseTest {
public static void main(String[] args) {
// Create a String of character having mixture of
// upper-case, lower-case letters, digits and symbols
// in between just for a test
String characters = "hH1u2U3b4B5b sS9pPo0Ot^%T";
// we take the length of characters by length()
int length = characters.length();
// we than loop each character one by one
for(int i = 0; i < length; i++) {
// we store each character in a variable
// for each loop
char character = characters.charAt(i);
// checking for each character that its a Upper-case or Lower-case
// letter or not by calling Character class isUpperCase() method,
// and isLowerCase() by passing the character. It returns true
// if the character passed is lower-case or upper-case and false
// if not separately
if(Character.isUpperCase(character)) {
System.out.println("Given character : " + characters.charAt(i)
+ " is an Uppercase letter");
}
else if(Character.isLowerCase(character)) {
System.out.println("Given character : " + characters.charAt(i)
+ " is a Lowercase letter");
}
else {
System.out.println("Given character : " + characters.charAt(i)
+ " is neither Uppercase nor Lowercase letter");
}
}
}
}
Output of the program : 
