toy demo class

[Vamsi Kankipati]

Question:-
Create Class Toy with below attributes
name
category
price
discount

Create Class ToyDemo with main method. Create four toy objects with relevant data. Two objects should have category as “fruits” and other two objects should have category as “anmial”. Write a method in this class which will take all four toy objects as input. Additionally, it will also take category name as input. This method should return least price toy name (considering the discount as well) for specified category. If there is no specific category (e.g category as “fruits”, method should return message “no category found”.

Follow class outline diagram as given below. Ensure class attributes are private and other methods are coderanch. Use package “com” to build your solution.

NOTE: Use .equals for comparing String values instead of == operator. Search on net and find out why. Else discuss among colleagues.

Class Outline:

[Jeanne Boyarsky]

This looks like homework. Give it a shot and post where you get stuck. See DoYourOwnHomework for more on why it is important to work on it yourself.

[Vamsi Kankipati]

Jeanne Boyarsky wrote:This looks like homework. Give it a shot and post where you get stuck. See DoYourOwnHomework for more on why it is important to work on it yourself.

I got stucked here;
I am unable to instantiate the objects through the user inputs

Code:-

package com;

import java.util.Scanner;

public class ToyDemo {

	public static void main(String[] args) {
		
		Scanner s = new Scanner ( System.in);
		Toy one = new Toy();
		
	      System.out.println("Enter a string");
	      Toy one=  new one.name = in.nextLine();
	      
		Toy two = new Toy("banana","fruits",10,2);
		Toy three = new Toy("dog","animal",800,50);
		Toy four = new Toy("buffalo","animal",8000,250);
		System.out.println(" The Toy with least price is " + 
				getLeastPriceToy(one, two, three, four, "animal"));
	}
	
	public static String getLeastPriceToy(Toy one,Toy two,Toy three,Toy four,String category) {
		if(one.getCategory().equals(category)) 
			Toy to = one;
			if(two.getPrice()>to.getPrice())
				to = two;
		if(category.equals("animal")) 
			Toy to=three;
			if(four.getPrice()>to.getPrice())
				to = four;
			return to.getName();
				
	}
}
public class Toy{
	private String name;
	private String category;
	private double price;
	private double discount;
	
	public Toy(String name, String category, double price, double discount){
		this.name = name;
		this.category = category;
		this.price = price;
		this.discount = discount;
	}
	
	public double getPrice() {
		return price;
	}
	public void setPrice(double price) {
		this.price = price;
	}
	public double getDiscount() {
		return discount;
	}
	public void setDiscount(double discount){
		this.discount = discount;
	}
	public String getName() {
		return name;
	}
	public String getCategory() {
		return category;
	}
}

[Campbell Ritchie]

Welcome to the Ranch

I added code tags, which you should always use, to your post. Doesn't it look better
Unfortunately it shows some stylistic problems. You should always have a blank line between successive methods.
You also have four fields in the Toy class but only three setXXX and getXXX methods. Why? Also give the Toy class a toString method so you can write
System.out.println(myToy);
and you will get something you can actually read. Apart from that, don't change anything else in the Toy class.

You have correctly encapsulated your Toys by making all fields private. That means you cannot access them from outside the class. You have also correctly given it a constructor meaning you must enter all four pieces of data before you can create an instance. Then in the ToyDemo class, you are trying to access those fields and trying to create a Toy without passing all four fields. The compiler will never let you do that.
Never use the assignment operator twice as in line 13. Of course the types are wrong, and access is prohibited, so the compiler will not permit such code.

You will have to remove most of the code from the main method. Also remove the least price method, which looks confused. Create a Toy object using the constructor and print it out. Then add another Toy object. If you use a Scanner to enter the data you may need to call input.nextLine(); and do nothing with the returned value after each Toy object. This old post explains why.
Only when you have got all that lot working will you be able to look at the least price method.

[Vamsi Kankipati]

According to the outiline figure in the question, all the getXxx and setXxx methods are fulfilled and no extra methods are required. Am i correct ?

[Campbell Ritchie]

Isn't the class diagram a minimum? Aren't you allowed to add methods to it?

[Vamsi Kankipati]

Campbell Ritchie wrote:Isn't the class diagram a minimum? Aren't you allowed to add methods to it?

Only the methods in the outline should be used in the program.

[Henry Wong]

Vamsi Kankipati wrote:
I got stucked here;
I am unable to instantiate the objects through the user inputs

From a very quick look at your code, it is obviously that you are encountering compiler errors. Generally, it is a good idea to tell us what the compiler errors are ... and what you don't understand about the error message.

Henry

[Christopher Schneider]

I copy/pasted the code into an IDE, and there are many problems with the code as is.

First, are these two classes in separate files? If not, they need to be. The class name needs to match the file name, or you can use inner classes. I would recommend that you put the classes in separate files.

The Toy class is fine as-is. It's only holding data: getters and setters. The ToyDemo is where everything breaks down. You have no default constructor for Toy, so on line 10 you cannot instantiate a new Toy(). Remember, your constructor for a Toy is:

public Toy(String name, String category, double price, double discount)

Therefore, when you say

Toy one = new Toy()

it doesn't work because

new Toy()

expects a name, category, price, and discount. You instantiated a toy correctly on lines 15, 16, and 17:

Toy two = new Toy("banana","fruits",10,2);
Toy three = new Toy("dog","animal",800,50);
Toy four = new Toy("buffalo","animal",8000,250);

because they match the constructor with a name, category, price, and discount.

There may be confusion here with the default constructor. If you do not supply a constructor, the compiler generates a default constructor that accepts no arguments. However, you've created a constructor for Toy, so no default constructor is generated.

Now the elephant in the room is line 13:

Toy one=  new one.name = in.nextLine();

I have absolutely no idea what's going on here. What are you trying to do?

[muralikrishna meda]

I got stucked here .. can you please help me

// ToyDemo.java

package com;

public class ToyDemo {

	
	public static void main(String[] args) {
		
		Toy one=new Toy("Banana","fruit",100,10.5); 
		Toy two=new Toy("Orange","fruit",300,30);
		Toy three=new Toy("Lion","animal",50,5);
		Toy four=new Toy("Tiger","animal",70,7);
		System.out.println(getLeastPriceToy(one, two, three, four,"fruit"));
		System.out.println(getLeastPriceToy(one, two, three, four,"animal"));
	}

	
	public static String getLeastPriceToy(Toy one, Toy two, Toy three, Toy four,
			String category) {
	
		Toy ansToy = one;
		if(two.getCategory().equals(category) &&
                        (two.getPrice()*two.getDiscount())<(ansToy.getPrice()*ansToy.getDiscount())){
			ansToy =two;
		}
		if(three.getCategory().equals(category) &&
                        (three.getPrice()*three.getDiscount())<(ansToy.getPrice()*ansToy.getDiscount())){
			ansToy =three;
		}
		if(four.getCategory().equals(category) &&
                        (four.getPrice()*four.getDiscount())<(ansToy.getPrice()*ansToy.getDiscount())){
			ansToy =four;
		}
		return ansToy.getName();
	}

}

[Carey Brown]

Edit your post and put in Code tags as previously requested.

It is not clear where exactly you are stuck. Does it compile? Does it run? Does it throw an exception? ...

[Carey Brown]

You repeat this pattern multiple times

x.getPrice() * x.getDiscount()

Your code would be more readable if your Toy class had an additional method called getDiscountedPrice() that did this.

[Campbell Ritchie]

New user, who probably doesn't know about code tags yet. I shall add them, and break the worst of the long lines, so he can see how to do it. Doesn't it look better now

Can you put the arguments into an array/list or similar? That would be far better for finding lowest price than all those if statements. Maybe the ... operator would help create the array.

And,welcome to the Ranch

[Carey Brown]

On line 22 you have

Toy ansToy = one;

The problem with this is that "one" may or may not be of the correct Category.