Hackerrank’in 30 Days of Code içerisinde bulunan “Day 4: Class vs. Instance” sorusunun açıklaması ve çözümü. Bu soruda sınıf ve field’lar üzerinde işlemler yapıyoruz.

► Hackerrank 30 Days of Code Çözümleri – Day 4: Class vs. Instance: https://www.hackerrank.com/challenges/30-class-vs-instance/problem

► Problem açıklaması:

Objective

In this challenge, we’re going to learn about the difference between a class and an instance; because this is an Object Oriented concept, it’s only enabled in certain languages. Check out the Tutorial tab for learning materials and an instructional video!

Task

Write a Person class with an instance variable, age, and a constructor that takes an integer, initialAge, as a parameter. The constructor must assign initialAge to age after confirming the argument passed as initialAge is not negative; if a negative argument is passed as initialAge, the constructor should set age to 0 and print Age is not valid, setting age to 0.. In addition, you must write the following instance methods:

yearPasses() should increase the age instance variable by 1.

amIOld() should perform the following conditional actions:

If age less than 13, print You are young..

If age bigger or equal than 13 and age less than 18, print You are a teenager..

Otherwise, print You are old..

To help you learn by example and complete this challenge, much of the code is provided for you, but you’ll be writing everything in the future. The code that creates each instance of your Person class is in the main method. Don’t worry if you don’t understand it all quite yet!

Note: Do not remove or alter the stub code in the editor.

Input Format

Input is handled for you by the stub code in the editor.

The first line contains an integer, T (the number of test cases), and the T subsequent lines each contain an integer denoting the age of a Person instance.

Constraints

Output Format

Complete the method definitions provided in the editor so they meet the specifications outlined above; the code to test your work is already in the editor. If your methods are implemented correctly, each test case will print or lines (depending on whether or not a valid was passed to the constructor).

Sample Input

4

-1

10

16

18

Sample Output

Age is not valid, setting age to 0.

You are young.

You are young.

You are young.

You are a teenager.

You are a teenager.

You are old.

You are old.

You are old.

The extra line at the end of the output is supposed to be there and is trimmed before being compared against the test case’s expected output. If you’re failing this challenge, check your logic and review your print statements for spelling errors.