Solution.java

//Problem: https://www.hackerrank.com/challenges/class-vs-instance
//Java 8
public class Person {
    private int age;	
  
	public Person(int initialAge) {
  		// Add some more code to run some checks on initialAge
        if(initialAge < 0)
        {
            this.age = 0; System.out.println("Age is not valid, setting age to 0.");
        }
        else
            this.age = initialAge;
	}

	public void amIOld() {
  		// Write code determining if this person's age is old and print the correct statement:
        if(this.age < 13)
            System.out.println("You are young.");
        else if(this.age < 18)
            System.out.println("You are a teenager.");
        else
            System.out.println("You are old.");
	}

	public void yearPasses() {
  		// Increment this person's age.
        this.age++;
	}