Final exam review Spring2007:Understanding inheritance

Final exam review Spring2007:Understanding inheritance

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Questions? Answers? Comments?

> Superhero batman = new Superhero(); would just work, no output?
> Superhero leo = new NinjaTurtle(0); would also work, no output
> leo.introduce(); —-> "I'm Leonardo"
> batman.introduce(); —-> "Hello. I am Batman. And I am weak"

When you create a method in a subclass that overrides a method from the superclass, how do you invoke the superclass method's behavior? What constraints are there for doing this in a constructor of a subclass?......

For the constructor you use super(). For invoking the super class's method, you do super.methodName(var1 var2) . Dawn Finney

Wouldn't you just cast 'this' to the superclass? What are the constraints??

Don't do that. It just sounds like a bad idea. I have no idea what it'll actually do, but I really don't want to crash my computer right now. Dawn Finney.

Question: So if you had 'public class Agent extends Turtle, and inside of that class there's a method like this:

public Agent (int x, int y, ModelDisplay modelDisplayer, Simulation thisSim) {
    // let the parent constructor handle it
    super(x,y,modelDisplayer);
    init(thisSim);
  }

..... is the parent constructor in this case the one inside of Turtle? and by using super, you're allowing the method inside of Turtle to handle it? or vice versa??|

Here, you are calling the parent's constructor from the child class. Dawn Finney.

Question: for the rewriting of the DrawableNode class question, since LLNode can do everything DrawableNode can, wouldn't you just need this?:

public class DrawableNode extends LLNode{
  }

You have to consider the change to the child's constructor as well. Dawn Finney.

Understanding Inheritance
I got this answer for the line—- leo.introduce();
Hello. I am Leonardo. And I am strong.
batman.introduce();
Hello. I am Batman. And I am weak.

Is this correct?? Am I assuming correctly that the object leo will use the constructor in the NinjaTurtle class, but it will use the method introduce() from the Superhero class?

I think that leo.introduce() uses the introduce method from the ninja turtle class because of dynamic binding

Modifications made to DrawableNode class:

public class DrawableNode extends LLNode{
public DrawableNode(){
super();
}
}

is that right? we have to take out the global variable, public DrawableNode next, too, correct?

Yeah. Dawn Finney.

For the inheritance you don't need the quotes (i think)
I'm Leonardo
Hello. I am Batman. And I am weak.

What constraints are there for doing this in a constructor of a subclass?...... Having the same constructor in the subclass, makes it basically the same thing as its superclass?? help!

What....I don't understand the question. What is the "this" you are referring to? Dawn Finney.

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Final Review-Spring 2007 last edited on 23 April 2007 at 11:13 pm by c-76-17-114-206.hsd1.ga.comcast.net