Talk is cheap. Show me the code.
Problem : https://www.hackerrank.com/challenges/java-iterator/problem
Solution :
Problem : https://www.hackerrank.com/challenges/java-instanceof-keyword/problem
Problem : https://www.hackerrank.com/challenges/java-interface/problem
Problem : https://www.hackerrank.com/challenges/java-abstract-class/problem
Problem : https://www.hackerrank.com/challenges/java-inheritance-1/problem