I get the right output but it wont pass

Question about the task

Resolved

So when I ran the solution in intellij I literally got the right solution. I put null values for the Human father and Human mother reference which I think may be the issue because I think it may be secretly asking me to reference both constructors(which I don't understand). If that's the case I still don't get the point because I get the right output. Can someone please explain this to me so I can pass this exercise and move on to the next level?

Create the Human class with String name, boolean sex, int age, Human father, and Human mother fields. Create and populate objects so that we end up with: Two grandfathers, two grandmothers, one father, one mother, and three children. Display the objects on the screen.

Note:
If you write your own String toString() method in the Human class, then it will be used to display the object on the screen.

Example output:
Name: Anna, sex: female, age: 21, father: Paul, mother: Kate Name: Kate, sex: female, age: 55 Name: Ben, sex: male, age: 2, father: Michael, mother: Anna …

Requirements:

The program must not read data from the keyboard.
Add the following fields to the Human class: String name, boolean sex, int age, Human father, and Human mother.
Add a constructor: public Human(String name, boolean sex, int age).
Add a constructor: public Human(String name, boolean sex, int age, Human father, Human mother).
Create 9 different Human objects (4 objects without a father and mother and 5 objects with them).
Display all the created objects on the screen.

package com.codegym.task.task07.task0724; /* Family census */ public class Solution { public static void main(String[] args) { Human grandFather1 = new Human("Alfonso",true,86,null,null); Human grandMother1 = new Human("Irma",false,84,null,null); Human grandFather2 = new Human("David",true,96,null,null); Human grandMother2 = new Human("Marry",false,94,null,null); Human father = new Human("Paul",true,60,grandFather2,grandMother2); Human mother = new Human("Robyn",false,59,grandFather1,grandMother1); Human child1 = new Human("Christopher",true,26,father,mother); Human child2 = new Human("Brianna",false,23,father,mother); Human child3 = new Human("Bunkie",false,12,father,mother); System.out.println(grandFather1); System.out.println(grandMother1); System.out.println(grandFather2); System.out.println(grandMother2); System.out.println(father); System.out.println(mother); System.out.println(child1); System.out.println(child2); System.out.println(child3); } public static class Human { private String name; private boolean sex; private int age; Human father; Human mother; public Human(String name, boolean sex, int age){ this.name = name; this.sex = sex; this.age = age; } public Human(String name, boolean sex, int age, Human father, Human mother){ this.name = name; this.sex =sex; this.age = age; this.father = father; this.mother = mother; } public String toString() { String text = ""; text += "Name: " + this.name; text += ", sex: " + (this.sex ? "male" : "female"); text += ", age: " + this.age; if (this.father != null) text += ", father: " + this.father.name; if (this.mother != null) text += ", mother: " + this.mother.name; return text; } } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

21 October 2020, 15:24

solution

I agree with both previous posts. In addition, The validation system will test your code by replacing methods, streams, args, etc with pre programmed data to ensure that your code "hits" all the points. Often times those points aren't fully spelled out in the conditions, and more frustratingly when a point "fails" there isn't necessarily going to be a good explanation as to why. This makes sense as there can literally be an infinite amount of ways to fail, though never an infinite amount of explanations for each of them. The best thing I can recommend, moving forward, when a point fails when you are more than positive that your code is correct, is to re-read the conditions/requirements again and try to identify the point your code could be missing. In this task you correctly assumed the likely answer (I put null values for the Human father and Human mother reference which I think may be the issue because I think it may be secretly asking me to reference both constructors), which is good and you should not be afraid to experiment when you think you know what may be the problem between code and validator. Just as an example, I could write this task as:

System.out.println("Name: Anna, sex: female, age: 21, father: Paul, mother: Kate");
System.out.println("Name: Kate, sex: female, age: 55");
System.out.println("Name: Ben, sex: male, age: 2, father: Michael, mother: Anna");
// etc

And while the output would technically be correct, I doubt it would hit the necessary points in the validation to pass. More so, if I had turned this in, the system probably wouldn't even be able to tell me why it fails. So good luck and don't be afraid to ask for help.

Chris

Level 19 , Newark, United States

22 October 2020, 15:47

Yeah, I often think too much and often forget to ask for help. Thank you though for helping me feel sain. I was going crazy trying to figure out what I did wrong when I really had the answer the whole time.

horst

Level 26 , Not in list

21 October 2020, 14:54

solution

I think I get your confusion. The short answer: You don't need to pass the null-Values to the Constructor in case of the grandparents. Some bits of explanation: In Java, you can have multiple different constructors for the same class. This is actually a very useful feature, because it allows you to create objects of the same class, but passing a different amount of information to them. An arbitrary example: You want to create a class called "Output", which takes a String, formats and processes it nicely and finally outputs it to the console. You have written a formatString-method that does all the beautiful things to your string and your Constructor may look something like this:

public Output(String content) {
	formatString(content);
}

Now you want your class to optionally write the formatted string to a file with a certain name, but only if this filename is actually entered or known. Of course, you can write separate methods for that, but the nice and easy way is to simply add a second constructor to your class:

public Output(String content, String filename) {
	formatString(content);
	writeContentToFile(filename);
}

Now you can create an Output-object in two different ways: One simply prints to console, and the other prints to console and saves the output to a file. With that in mind, have a look at the Human class of the task again: It has two Constructors aswell: One in case the father and mother are known, and the other for "parentless" humans. So for the grandparents, you invoke the one constructor which only takes three arguments, and for their (grand)children you invoke the constructor with the two additional fields. Hope this helps, don't hesitate to ask. Happy Coding!

Chris

Level 19 , Newark, United States

22 October 2020, 15:46

Honestly, this helped a lot because I definitely needed a bit of refresher on what constructors are used for. Thank you so much for the detailed explanation.

Misiu

Level 41 , Gdansk, Poland

21 October 2020, 14:42

solution

You are right. Constructor with 3 parameters is for grandpas. Remove null values.

Chris

Level 19 , Newark, United States

22 October 2020, 15:48

Thank you! I fixed it and now I passed :)