Here is an example that compares two array and display the common elements between them.

public class FindCommonElement {
    public static void main(String args[]) {
        int[] arr1 = {1,2,3,4,5};
        int[] arr2 = {3,4,12,9,40,32,2};
        for(int i=0;i<arr1.length;i++){
            for(int j=0;j<arr2.length;j++){
                if(arr1[i]==arr2[j]){
                    System.out.println(arr1[i]);
                }
            }
        }
    }
}

Here is an example of Fibonacci Series without recursive approach.

public class Fibbonacci {
public static void main(String[] args) throws Exception {
      int num = 15;
                long[] series = new long[num];
                series[0] = 0;
                series[1] = 1;
                for(int i=2; i < num; i++){
                        series[i] = series[i-1] + series[i-2];
                }
                System.out.println("Fibonacci Series upto " + num);
                for(int i=0; i< num; i++){
                        System.out.print(series[i] + " ");
                }
        }
}

Here is an example of reversing number where user is allowed to enter the number which is to be reversed.

import java.io.*;
class ReverseNumber
{
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter Number");
int num= Integer.parseInt(br.readLine());
int n=num;
int rem=0;
int rev=0;
while(n!=0)
{
rem = n%10;
rev = rev*10+rem;
n=n/10;

}
System.out.println("Reverse Number : " + rev);
}
}