Thread: Another question abt mutators and accessors...

ok same assignment(discussed in the question abt mutators) new problem, in my class gorilla, we have to give it a pet cat with the accessors and mutators for the pet cat in the gorilla class... this is what I have so far

 
    private int Gweight;
    private String Gname;
    private Cat pet;
    private String cat; // Java made me add this variable for whatever the reason (the previous code used didn't work for some reason)
 
 
    public Cat getPet() {
        return pet;
    }
 
 
    public void setPet(String c) {
         this.cat = c; //this is the problem, I was wondering why it can't be this.pet=c; instead
    } 
//the rest of the coding is fine my prof checked it earlier today

the setPet method in particular. maybe i'm misunderstanding the way the mutator works but I figured that

public void setPet (String c) {
this.pet = c;

should work....but for some reason Java gives me an error message saying "incompatible types required: Cat found: String"

No, that shouldn't work, and the compiler is as usual correct. You're trying to assign a String to a Pet variable, and that won't work. You can only assign a Pet object to a Pet variable. Notice how you declare your pet variable:

Cat pet;

Ok that makes more sense but does it make a difference that the variable is like that because it's supposed to call on the cat class that is already written and correct since my prof checked it today. now the problem is calling those methods in my harness that says the gorilla has a pet cat here's what I have so far

 public static void main(String[] args) {
 
 
 
 
        Gorilla G1 = new Gorilla();
        Gorilla G2 = new Gorilla("Godzilla", 85);
 
 
 
 
        System.out.println(G1);
        System.out.println(G2);
        System.out.println("\n");
 
 
        Cat C1= new Cat();
        Cat C2 = new Cat();
 
        C2.setName("Rocket");
        C2.setColor("orange");
 
 
        G1.setPet("Brainy");
        G2.setPet("Twinkle Toes");
         System.out.println(G1.getPet().getName()); //THIS IS THE PROBLEM
 
        System.out.println(C1);
        System.out.println(C2);
        System.out.println("\n");
 
    }
}

The compiler will run it, but then Java gives me this error " Exception in thread "main" java.lang.NullPointerException at hwk11.tmarshall5.Hwk11Tmarshall5.main(Hwk11Tmarsha ll5.java:41) Java Result: 1"...and no matter what I do to fix it and still make sure the gorilla gets and pet and what the pet they get (if that makes sense)

The compiler can't compile that code, not unless you changed the Gorilla pet variable to a String variable, and hopefully you didn't do this. You need to show us how you "fixed" your Gorilla class.

No I didn't change any of the variables

Oh, I see what you did. You need to get rid of that cat variable:

    private String cat; // Java made me add this variable for whatever the reason (the previous code used didn't work for some reason)

And no, Java didn't make you add this variable. Just get rid of it and only use the pet variable in your setPet method. Give that method a Cat parameter and pass in a Cat object into that method as we discussed, not a String.

Is this what you meant?

 public void setPet(String Cat) {
         this.pet = Cat;
    }

Because if so, Java gives and error stating "incompatible types required: Cat found: String"

--- Update ---

Sorry just saw the post abt the gorilla class...here it is

public class Gorilla {
 
    private int Gweight;
    private String Gname;
    private Cat pet;
 
 
    public Cat getPet() {
        return pet;
    }
 
 
    public void setPet(String Cat) {
         this.pet = Cat; //this is the error
    }
 
 
    public int getGweight() {
        return this.Gweight ;
    }
 
 
 
    public String getGname() {
        return this.Gname;
    }
 
 
    public void setGweight(int x) {
        this.Gweight = x; 
    }
 
 
    public void setGname(String g) {
        this.Gname = g;
    }
 
    public Gorilla() {
        this.Gname = "King Zeus";
        this.Gweight = 1;
    }
 
 
    public Gorilla(String g, int w) {
        this();
        this.Gname = g;
        this.Gweight = w;
    }
 
 
 
 
    public String toString() {
        return "The Gorilla's name is " + Gname + ", and the weight of that Gorilla is:  " + Gweight;
    }
 
}

Originally Posted by Vessel06

Is this what you meant?

 public void setPet(String Cat) {
         this.pet = Cat;
    }

Because if so, Java gives and error stating "incompatible types required: Cat found: String"

Yep, and again the compiler is right. Again, don't use a String parameter for this method. What parameter type should you use instead?

Note: you should not have a parameter named "Cat" as this will be very confusing since you have a class of the same name.

But when I simply put

public void setPet(c) {
         this.pet = c; //this is the error
    }

Java gives another error stating that an identifier still needs to be made...unsure what I should use in the parameter to compile

Originally Posted by Vessel06

But when I simply put

public void setPet(c) {
         this.pet = c; //this is the error
    }

Java gives another error stating that an identifier still needs to be made...unsure what I should use in the parameter to compile

Have a look at the method tutorial to see how to write methods. The parameter always needs it's type declared, and in fact you've done this with your other methods, and in fact already did it with this method, but you just had the wrong type (String). Now you've given the parameter *no* type, and this can't work. Try to give it a *correct* type. You can do it -- just look at your notes or the tutorial.

YOU SIR ROCK!!!! I passed in the right identifier

 public void setPet(Cat c) {
         this.pet = c; 
    }

Now the problem is to make sure it all runs in the harness when I give the gorilla a pet cat as I showed earlier in one of the previous post showing my Gorilla Class

Originally Posted by Vessel06

YOU SIR ROCK!!!! I passed in the right identifier

 public void setPet(Cat c) {
         this.pet = c; 
    }

There you go!

Now the problem is to make sure it all runs in the harness when I give the gorilla a pet cat as I showed earlier in one of the previous post showing my Gorilla Class

You should be able to fix your harness so that it now works.

Ok...this is the prof's example/instruction "In your harness, check that your new accessor and mutator work. For instance, if you have a Gorilla koko and a Cat fluffy, you should be able to say

koko.setPet(fluffy);
//And if you then said
 
System.out.println(koko.getPet().getName());
//you should get the same result as
System.out.println(fluffy.getName());"

however those codes aren't working for me (and they do have the appropriate variable names from my project)

the one that is working for me is

        G1.setPet(C2);
        G2.setPet(C1);
        System.out.println(G1.getPet());

My question is if that code above says that a gorilla gets a pet cat...because in my output it just reprints a previous statement

--- Update ---

Just in case you need to see the rest of my harness...here it is

public static void main(String[] args) {
 
 
 
 
        Gorilla G1 = new Gorilla();
        Gorilla G2 = new Gorilla("Godzilla", 85);
 
 
 
 
        System.out.println(G1);
        System.out.println(G2);
        System.out.println("\n");
 
 
        Cat C1= new Cat();
        Cat C2 = new Cat();
 
        C2.setName("Rocket");
        C2.setColor("orange");
 
 
        G1.setPet(C2);
        G2.setPet(C1);
        System.out.println(G1.getPet());
 
 
        System.out.println(C1);
        System.out.println(C2);
        System.out.println("\n");
 
    }
}

You should show what is wrong with your current code. What output are you seeing vs. what are you expecting.

This is the current code giving the issue

        G1.setPet(C2);
        G2.setPet(C1);
        System.out.println(G1.getPet().getGname);
 
 
The output I'm getting is " The Gorilla's name is King Zeus, and the weight of that Gorilla is:  1
The Gorilla's name is Godzilla, and the weight of that Gorilla is:  85
 
 
The cat's name is Rocket, and the color of the cat is: orange
The cat's name is Mr. Fluffmiester, and the color of the cat is: tuxedo
The cat's name is Rocket, and the color of the cat is: orange" //This one doesn't say anything about the gorilla HAVING either one of cats as a pet cat