Can anyone help me in my Assignment

**nono** · 11-10-2010, 01:48 PM

hi

I really hate java , I have a problem with it

what can I do to enjoy with it

and I have Assignment that cut off date 20 nov

I solve it but I'm not sure that is true !

can anyone help me here or in my email :)

**masijade** · 11-10-2010, 01:51 PM

Lots of people can. Ask a specific question.

**KevinWorkman** · 11-10-2010, 01:52 PM

...what's your question?

Read this: How To Ask Questions The Smart Way

**nono** · 11-10-2010, 01:57 PM

there are errors in this codes :

Dancer sam = new Dancer();

Semantic error: Typed variable declaration : Constructor error: Can't create instance of an interface: interface Dancer

DancerFrog alice = new Frog();
Semantic error: Cannot cast Frog to DancerFrog

kermit.danceSteps();
Semantic error: Attempt to resolve method: danceSteps() on undefined variable or class name: kermit

- helen.getReady();
Semantic error: Attempt to resolve method: getReady() on undefined variable or class name: helen

I want to know detailed explanation of Semantic error in these code

:(

**KevinWorkman** · 11-10-2010, 02:03 PM

What don't you understand about the errors?

Dancer is an interface. You can't directly instantiate an interface.
Frog is not an extension of DancerFrog. Perhaps the other way around?
The variables kermit and helen are undefined in the score you're trying to access them.

It seems to me like you really need to go back to the basic tutorials or the early notes you took, if this is for a class.

**nono** · 11-10-2010, 02:22 PM

I am a beginner in Java and c++ and I have alots of Assignments and
Quizzes in this period ,,

ummm mean that this codes: helen.getReady(); + getReady(); I don’t use declarations to create variables that must provide methods to access values stored there.

kermit.danceSteps();

mean I must set a int value (Parameter)inside danceSteps();

right ??

I feel like I want to cry

really confused

**KevinWorkman** · 11-10-2010, 02:25 PM

Maybe if you broke down each of your problems into a separate SSCCE that recreated the error, we could explain what they mean. As of now, your questions are way too broad to provide any real help.

**nono** · 11-10-2010, 02:34 PM

ummmm thank you bro

I will see this link and try to solve the rest of the questions

**nono** · 11-11-2010, 08:46 AM

o

can anyone see to my Assignment in this link

is my solution correct

.. Is there a mistake ??

can help me in question 1 (ii) >> - DancerFrog alice = new Frog();
Semantic error: Cannot cast Frog to DancerFrog

and the last question2 (d)

please help me :(

**nono** · 11-11-2010, 08:14 PM

??

:o

:(

**nono** · 11-14-2010, 04:26 AM

:eek:

up :(

**al_Marshy_1981** · 11-14-2010, 04:30 AM

I am not clicking on some link when you can just as easily post your code here

**Fubarable** · 11-14-2010, 04:41 AM

Agree. If the code is too long to post here, then it's too long for us to review. Otherwise if you post it here (with code tags), we'll all have an idea of what your problem(s) may be and how to help you.

Best of luck!

**Fubarable** · 11-14-2010, 04:47 AM

Edit: My apologies: it seems that you did show what you've done for portions of your assignment.

**Fubarable** · 11-14-2010, 05:21 AM

Originally Posted by nono

I am a beginner in Java and c++ and I have alots of Assignments and
Quizzes in this period ,,

ummm mean that this codes: helen.getReady(); + getReady(); I don’t use declarations to create variables that must provide methods to access values stored there.

kermit.danceSteps();

mean I must set a int value (Parameter)inside danceSteps();

right ??

Correct. According to the Dancer interface:

Java Code:

public interface Dancer
{
  public void danceSteps(int n);
}

danceSteps takes an int parameter.

**nono** · 11-14-2010, 07:14 AM

I'm sorry for the inconvenience

o:o

(d) Suppose the following statement is executed:
DancerFrog frog2 = frog1;
How many variables are there? How many DancerFrog objects now exist? Explain your answer. [2 marks]

my Solution :

There are two variables : frog1 , frog2

And one object : DancerFrog

First we have this statement Frog frog1 = new Frog() which means we have created a new instance of the class Dancer Frog named frog1 and we set initial values: Position 1 and colour green

Also we have a new instance of the class DancerFrog named frog2 but we did n’t set initial values as frog1.

And for this part of statement : frog2 = frog1
assigned the address of the DanerFrog object referenced by frog1 to the variable frog2.

So both variables, frog1 and frog2 reference the same DanerFrog object.

This is what we mean in this statement : DancerFrog frog2 = frog1

::

it will be DancerDFrog or Frog ?

**Fubarable** · 11-14-2010, 12:29 PM

Originally Posted by nono

(d) Suppose the following statement is executed:
DancerFrog frog2 = frog1;
How many variables are there? How many DancerFrog objects now exist? Explain your answer. [2 marks]

my Solution :
There are two variables : frog1 , frog2

And one object : DancerFrog

Correct. There are two variables and one object which may be a DancerFrog object (I didn't see the constructor call, so the object can be a Frog object or an object of any class that derives from Frog such as DancerFrog).

First we have this statement Frog frog1 = new Frog() which means we have created a new instance of the class Dancer Frog named frog1 and we set initial values: Position 1 and colour green

frog1 does not reference a DancerFrog object but rather a Frog object. I don't know if its position property is one or the colour green since I have not seen the code for the Frog constructor.

Also we have a new instance of the class DancerFrog named frog2 but we did n’t set initial values as frog1.

I didn't see you setting initial values on frog1, so this statement confuses me.

And for this part of statement : frog2 = frog1
assigned the address of the DanerFrog object referenced by frog1 to the variable frog2.

So both variables, frog1 and frog2 reference the same DanerFrog object.

correct.

This is what we mean in this statement : DancerFrog frog2 = frog1

it will be DancerDFrog or Frog ?

Can you clarify this a bit?

**nono** · 11-14-2010, 08:50 PM

Originally Posted by Fubarable

Correct. There are two variables and one object which may be a DancerFrog object (I didn't see the constructor call, so the object can be a Frog object or an object of any class that derives from Frog such as DancerFrog).

frog1 does not reference a DancerFrog object but rather a Frog object. I don't know if its position property is one or the colour green since I have not seen the code for the Frog constructor.

Frog code in q1

I didn't see you setting initial values on frog1, so this statement confuses me.

also in q1:D

correct.

Can you clarify this a bit?

this is full Question and answer:

see the attachments