Variable name as datatype,keyword and class name.

 package com.company;

import java.util.Scanner;

class sum{
    int sum=0;

    public int func(int n){
        for(int i=1;i<=n;i++){
            for(int j=1;j<=i;j++){
                sum++;
                System.out.println(sum);
            }

        }
        return sum;
    }
}
public class Main {
    public static void main(String[] args) {
//sum obj= new sum();
//        System.out.println("Enter the value of n");
//        Scanner sc =new Scanner(System.in);
//        int n= sc.nextInt();
//        System.out.println(obj.func(n));
        System.out.println(0%2);
        int Integer = 9; // ---> Taking class name..
        int integer = 10;
        int String = 67; // ---> Taking class name..
        int string = 68;
        int Array = 89;
//        int int= 8; ---> This gives a syntax error. cannot take keywords as variable.
        System.out.println(Integer);
      

    }
}