java reason: actual and formal argument lists differ in length

Question

I need help creating a setter method for my code. I have created two setter methods for both of my string values, but I am A) not sure if they are implemented correct, and B) not sure how to call them so that they appear on the screen. Essentially I would like to be able to just call my lion and hippo classes and have them already have a name and a size, and not have to implement them inside my main function directly by inserting something like Hippo h = new Hippo("Tom", "42")

package game2;


public class Game2 {

    public static void main(String[] args) {
        //I am getting the error here, what I want to do is figure out how to 
        //get this to work and then declare a name and size for the animal
        Hippo h = new Hippo();
        Lion l = new Lion(); 
    }

}

---

package game2;

public abstract class Animal {
    private String name;
    private String Size; 

    public String getName() {
        return name; 
    }

    public String getSize() {
        return Size; 
    }

    public void setName(String name) {
        name = "Tom"; 
    }

    public void setSize(String name) {
        name = "42"; 
    }


    public Animal(String theName, String theSize) {
        name = theName; 
        Size = theSize; 
    }
 }

---

package game2;

public class Hippo extends Animal {

    public Hippo(String name, String Size) {
        super(name, Size);
    }
}

---

package game2;

public class Lion extends Animal{

    public Lion(String name, String Size) {
        super(name, Size);
    }
}    

Answer 1

Remember when implement constructor by your own, you are overload the default constructor. So you need to pass two arguments.

You didnot pass the arguments for constructors when you instantiate:

Hippo h = new Hippo();
Lion l = new Lion(); 

Because your class constructors expect two parameters.

public Hippo(String name, String Size) {
    super(name, Size);
}

And:

public Lion(String name, String Size) {
    super(name, Size);
}

Solutions:

Either you can pass arguments when you instantiating objects:

Hippo h = new Hippo("name", "33");
Lion l = new Lion("name", "22"); 

Or you need to implement overloaded constructors for these.

Read this to learn more about constructor overloading.

Answer 2

your code is not compiling because you are not using the right constructor, Both Hippo's and Lion's constructors expect two string arguments so you have to do something like:

Hippo h = new Hippo("myHippo", "220");
Lion l = new Lion("Simba", "400");

Answer 3

new Hippo()/Lion() is calling a function you don't have (empty constructor)

You have function Hippo(String name, String Size) which need 2 parameters

try new Hippo("Billy", "10")

Answer 4

Both Hippo's and Lion's constructors expect two string arguments - the name and the size. You need to pass them when you call the respective constructors. E.g.:

Hippo h = new Hippo("Happy", "Huge");
Lion l = new Lion("Leo", "Big"); 

Answer 5

If you want to decide the name and size after you have created your animal, you need a parameterless constructor. Currently all the constructors require you to pass 2 arguments. So write one!

Here is an example:

public Hippo() {
    setSize(insert default size here);
    setName(insert default name here);

}

Then, you can create a hippo like this:

Hippo hippo = new Hippo();
hippo.setName("Tom");