Java error: 56

[Daniel Kavanaugh]

Hi everyone,

I'm getting an error that reads 56: error: cannot find symbol on line findWholeInventory(cameras[3]); symbol: method findWholeInventory(Camera) location: class Inventory

I'm confused by this because I define this method in the class Camera:

public static double findWholeInventory(Camera[] cameras)
	{
		double sum = 0;
		for (int x = 0; x < cameras.length; x++)
		{
			sum += cameras[x].getInventoryValue();
		}
		return sum;
	}

and I have defined Camera in the Inventory class:

			Camera cameras[] = new Camera[3];
			Camera powershot = new DigitalCamera("Canon Powershot", "Electronics", 1, 5, 100, 500, 8);
			Camera cybershot = new DigitalCamera("Sony Cybershot", "Electronics", 2, 7, 200, 1400, 15);
			Camera elph = new DigitalCamera("Elph 300 HS", "Electronics", 3, 8, 50, 400, 7);
			cameras[0] = powershot;
			cameras[1] = cybershot;
			cameras[2] = elph;

DigitalCamera is a subclass that extends Camera, could that be a problem? Everything compiles fine except the inventory class with the aforementioned error. Do I just need to change the syntax on the array that it reads from?

[Praveen Kumar M K]

Can you please post the code of the Inventory class where you are making a call to findWholeInventory. It would be better to post the code of all the 3 classes if its possible.

[Daniel Kavanaugh]

That would certainly help. There's a lot of unneeded code in DigitalCamera, but I don't like changing things until I get everything working.

import java.awt.Graphics; //importing class Graphics
import javax.swing.JPanel; //importing class Jpanel
import java.util.Arrays; //importing class Arrays	
import java.util.Scanner; //importing class Scanner

public class Inventory
{
	public static void main( String[] args ) //main method begins execution of java application
	{
		Scanner input = new Scanner( System.in); //instantiating a scanner to take input from command line
			String nameOfProduct = "";
			String productDepartment = "";
			int itemNumber = 0;
			int numberOfStock = 0;
			int priceOfUnit = 0;
			String systemStatus = "";
			String alphabetSort = "";
			Camera cameras[] = new Camera[3];
			Camera powershot =
               new DigitalCamera("Canon Powershot", "Electronics", 1, 5, 100, 500, 8);
			Camera cybershot =
               new DigitalCamera("Sony Cybershot", "Electronics", 2, 7, 200, 1400, 15);
			Camera elph =
               new DigitalCamera("Elph 300 HS", "Electronics", 3, 8, 50, 400, 7);
			cameras[0] = powershot;
			cameras[1] = cybershot;
			cameras[2] = elph;
			
		System.out.printf( "Welcome to Inventory. Would you like to proceed? Y/N" );
		systemStatus = input.nextLine();
		System.out.println();

		while(systemStatus.equalsIgnoreCase("y"))
		{

		findWholeInventory(cameras[3]);			
		System.out.printf( "What is your product?"); //displays user prompt
		nameOfProduct = input.nextLine(); //reads nameOfProduct variable from user
		System.out.println(); //prints a blank line for organization
		if(nameOfProduct.equalsIgnoreCase("Canon Powershot"))
		{
		System.out.println(cameras[0]);
		}
		if(nameOfProduct.equalsIgnoreCase("Sony Cybershot"))
		{
		System.out.println(cameras[1]);
		}
		if(nameOfProduct.equalsIgnoreCase("Elph 300 HS"))
		{
		System.out.println(cameras[2]);
		}
	}
}
}

public class Camera
{
	int itemNum;
	String productName;
	String productDepo;
	int stockNum;
	int unitPrice;
	double inventoryValue;
	double imageResolution;

	//constructor to initialize product name, product department, item number, number of stock, and unit price
	public Camera( String productName,
              String productDepo, int itemNum, int stockNum,
               int unitPrice, double inventoryValue, double imageResolution )
	{
		super();
		this.itemNum = itemNum;
		this.productName = productName;
		this.productDepo = productDepo;
		this.stockNum = stockNum;
		this.unitPrice = unitPrice;
		this.imageResolution = imageResolution;
		createInventoryValue();
	} //end Camera constructor
	
	//method for retrieving string variable productName
	public String getProductName(String ProductName)
	{
		return(productName);
	}

	//method for assigning value of stockNum times unitPrice to variable inventoryValue
	 private void createInventoryValue()
	{
		inventoryValue = stockNum * unitPrice;
	}

	//method for retrieving int variable inventoryValue 	
	public double getInventoryValue()
	{
		return inventoryValue;
	}

	public String toString()
	{
		return ("Product Name: " + productName + "\n" + "Product Department: " +
               productDepo + "\n" + "Amount in Stock: " + stockNum + "\n" + "Unit Price: "
               + unitPrice + "\n" + "Inventory Value: " + inventoryValue + "\n" +
                "Image Resolution: " + imageResolution);
	}
	public static double findWholeInventory(Camera[] cameras)
	{
		double sum = 0;
		for (int x = 0; x < cameras.length; x++)
		{
			sum += cameras[x].getInventoryValue();
		}
		return sum;
	}
}

class DigitalCamera extends Camera
{
	int num;
	private String name;
	private String depo;
	int stock;
	int price;
	double valueOfInventory;
	double restockedInventory;
	double imageResolution;
	double rez;

	public DigitalCamera( String name,
                String depo, int num, int stock, int price, double valueOfInventory, double rez )
	{
		super( name, depo, num, stock, price, valueOfInventory, rez );
		productName = name;
		productDepo = depo;
		itemNum = num;
		stockNum = stock;
		unitPrice = price;
		calculateInventoryValue();
		imageResolution = rez;

	}
		
	public void setProductName( String name )
	{
		productName = name;
	}

	public String getProductName()
	{
		return productName;
	}

	public void setProductDepartment( String depo )
	{
		productDepo = depo;
	}
	
	public String getProductDepartment()
	{
		return productDepo;
	}
	
	public void setItemNumber( int num )
	{
		itemNum = num;
	}
	
	public int getItemNumber()
	{
		return itemNum;
	}

	public void setStockNum( int stock )
	{
		stockNum = stock;
	}

	public int getStockNum()
	{
		return stockNum;
	}

	public void setUnitPrice( int price )
	{
		unitPrice = price;
	}

	public int getUnitPrice()
	{
		return unitPrice;
	}

	private void calculateInventoryValue()
	{
		inventoryValue = stockNum * unitPrice;
		restockedInventory = inventoryValue + (inventoryValue * .05);
	}
	
	public double getInventory()
	{
		return restockedInventory;
	}
	
	public void setImageResolution( double rez )
	{
		imageResolution = rez;
	}

	public double getImageResolution()
	{
		return rez;
	}
 
	public String toString()   
    	{   
        return ("Product Name: " + productName + "\n" + "Product Department: " + productDepo    
        + "\n" + "Amount in Stock: " + stockNum + "\n" + "Unit Price: " + unitPrice + "\n" +
          "Inventory Value: " + restockedInventory + "\n" + "Image Resolution: " + rez);   
    	}
}

[fred rosenberger]

also, if you'd post the complete error message

edit:
so i pulled your code and compiled it, and got this:

C:\slop>javac Inventory.java
Inventory.java:60: cannot find symbol
symbol : method findWholeInventory(Camera)
location: class Inventory
findWholeInventory(cameras[3]);
^
1 error

This tells you that on line 60, the compiler couldn't resolve the method - it has NO idea where to find the definition of this method.

You defined in in the Camera class, so you have to tell it to look there:

Camera.findWholeInventory(cameras[3]);

However, that will give you a new error. See if you can figure out the problem with that...

[Daniel Kavanaugh]

Inventory.java:56: error: cannot find symbol
findWholeInventory(cameras[3]);
^
symbol: method findWholeInventory(Camera)
location: class Inventory

[Praveen Kumar M K]

Daniel, referring to line 60 of your Inventory class(the call to findWholeInventory). From Inventory class's perspective, does it know anything about findWholeInventory? Is there way for it to call that method which is actually in Camera class?

[fred rosenberger]

also, note that this:

Camera cameras[] = new Camera[3];  
Camera powershot = new DigitalCamera("Canon Powershot", "Electronics", 1, 5, 100, 500, 8);  
Camera cybershot = new DigitalCamera("Sony Cybershot", "Electronics", 2, 7, 200, 1400, 15);  
Camera elph = new DigitalCamera("Elph 300 HS", "Electronics", 3, 8, 50, 400, 7);  
cameras[0] = powershot;  
cameras[1] = cybershot;  
cameras[2] = elph;  

can be simplified to this;

Camera cameras[] = new Camera[3];  
cameras[0] = new DigitalCamera("Canon Powershot", "Electronics", 1, 5, 100, 500, 8);  
cameras[1] = new DigitalCamera("Sony Cybershot", "Electronics", 2, 7, 200, 1400, 15);  
cameras[2] = new DigitalCamera("Elph 300 HS", "Electronics", 3, 8, 50, 400, 7);  

[Daniel Kavanaugh]

So Should it read cameras.findWholeInventory(cameras[3]); ?

[Daniel Kavanaugh]

Also, would it be possible for me to display all the elements in these arrays within a GUI?

[Praveen Kumar M K]

Daniel Kavanaugh wrote:So Should it read cameras.findWholeInventory(cameras[3]); ?

No it shouldnt. Have a look at how Fred has called it. Are you aware of static methods and variables?

[fred rosenberger]

Daniel Kavanaugh wrote:Also, would it be possible for me to display all the elements in these arrays within a GUI?

of course it would...but GUI code should be completely separate from the other code. You should get it to work from the command line first, and only then worry about the GUI.

[fred rosenberger]

Daniel Kavanaugh wrote:So Should it read cameras.findWholeInventory(cameras[3]); ?

Camera is the name of a class.

cameras is the name you gave to a reference variable that points to an array that can hold Camera objects.

Therefore...

Camera is not the same thing as cameras.

[Campbell Ritchie]

Daniel Kavanaugh wrote: . . .

DigitalCamera is a subclass that extends Camera, could that be a problem? . . .

No. Plain and simple: if you haven’t made some dreadful error in how you extended the Camera class, then that will not cause any problems. Fred R has already given you a heavy hint as to what the problem you noticed is.


What Fred didn’t know, because he was writing the reply before you posted all your code, is that you have in fact made a dreadful error in subclassing the Camera class. An error which has to be corrected with generous use of three keys which will really have you cursing me. Ctrl-A delete.

Well, not quite. You have not actually subclassed the Camera class. You have written a new class which says it subclasses it, but you have added all sorts of new information. You have two names, two prices, etc., in the Digitalcamera class. One inherited from Camera, and the other hidden. Look at our FAQ; hiding applies to fields just as it does to methods.
Remove any constructors which don’t do what you want. You want to record make, pixels, price, for every camera. so make sure to get rid of constructors which don’t take all those data. You will probably only want one constructor. Get rid of all the others. Be ruthless. If you want your code to work, you want make pixels price recorded in every Camera object, so make d*mn sure all constructor calls give you that info. And you do that by making sure that is the only constructor tanybody can find.
By the way: are you recording how many Cameras there are in the Camera class? I don’t think that is really part of the Camera class. I think it is part of something else, maybe an Inventory class.

[Campbell Ritchie]

Daniel Kavanaugh wrote:Also, would it be possible for me to display all the elements in these arrays within a GUI?

Until you have got the Camera and DigitalCamera classes working at the command line, you forget there even is such a thing as a GUI.

[Campbell Ritchie]

Part 2
Remove every field from the DigitalCamera class which is repeated from the Camera class. You use the fields which are in the Camera class. They should have private access in Camera, but you can gain access if necessary via the getXXX methods. You may find the only field declared in the Digital class is pixels.
Remove every setXXX and getXXX method from the Digital class which appears to be repeated from Camera.
Remove every constructor which doesn’t set up all your fields. I suggest you change your constructor to use the this. idiom you had in Camera. It allows you to use better parameter names.

What you haven’t noticed yet, is how much smaller your digital class is becoming. One setter/getter pair, one field and one constructor. Your constructor will need to pass lots of information to the Camera class with the super(make, price...); call.

Now all you need to do is simplify that DigitalCamera#toString() method. Find out about super.toString(), which I shall not say any more about at this point.

Now, you have a class with subclasses Camera. And see how much simpler it is.

And I see Fred has already told you not to use a GUI. And have you worked out what the error you noticed was?

[Campbell Ritchie]

When I said remove constructors which don’t initialise all your fields, that applies to both classes.

[Daniel Kavanaugh]

Thanks for posting, guys. Everything compiles now, but unfortunately, I'm still a little confused about some of the stuff stated in your posts. I really apologize.

I've been attempting to correct this program so that it can be displayed in a gui (although all I need it to do is display the arrays in something that isn't the command prompt). Should I just continue, or are there things I absolutely need to fix before displaying the data? Right now, it displays all necessary data, except the result of the findWholeInventory method.

import java.util.Scanner; //importing class Scanner


public class Inventory
{
		

	public static void main( String[] args ) //main method begins execution of java application
	{
	
		

		Scanner input = new Scanner( System.in); //instantiating a scanner to take input from command line



		
	
			String nameOfProduct = "";
		
			String productDepartment = "";
			
			int itemNumber = 0;
	
			int numberOfStock = 0;

			int priceOfUnit = 0;
			
			String systemStatus = "";
			
			String alphabetSort = "";

			Camera cameras[] = new Camera[3];
			Camera powershot = new DigitalCamera("Canon Powershot", "Electronics", 1, 5, 100, 500, 8);
			Camera cybershot = new DigitalCamera("Sony Cybershot", "Electronics", 2, 7, 200, 1400, 15);
			Camera elph = new DigitalCamera("Elph 300 HS", "Electronics", 3, 8, 50, 400, 7);
			cameras[0] = powershot;
			cameras[1] = cybershot;
			cameras[2] = elph;
			


			
		System.out.println(cameras[0]);
		System.out.println(cameras[1]);
		System.out.println(cameras[2]);	
		
		Camera.findWholeInventory(cameras);


			

}

}

I did not change Camera.

public class Camera
{

	
	int itemNum;
	String productName;
	String productDepo;
	int stockNum;
	int unitPrice;
	double inventoryValue;
	double imageResolution;

	//constructor to initialize product name, product department, item number, number of stock, and unit price
	public Camera( String productName, String productDepo, int itemNum, int stockNum, int unitPrice, double inventoryValue, double imageResolution )
	{
		super();
		this.itemNum = itemNum;
		this.productName = productName;
		this.productDepo = productDepo;
		this.stockNum = stockNum;
		this.unitPrice = unitPrice;
		this.imageResolution = imageResolution;
		createInventoryValue();
	} //end Camera constructor
	
	//method for retrieving string variable productName
	 
	public String getProductName(String ProductName)
	{
		return(productName);
	}

	//method for assigning value of stockNum times unitPrice to variable inventoryValue

	 private void createInventoryValue()
	{
		inventoryValue = stockNum * unitPrice;
	}
	
	//method for retrieving int variable inventoryValue 
	
	public double getInventoryValue()
	{

		return inventoryValue;
	}

	public String toString()
	{
		return ("Product Name: " + productName + "\n" + "Product Department: " + productDepo 
		+ "\n" + "Amount in Stock: " + stockNum + "\n" + "Unit Price: " + unitPrice + "\n" + "Inventory Value: " + inventoryValue + "\n" + "Image Resolution: " + imageResolution);
	}
	public static double findWholeInventory(Camera[] cameras)
	{
		double sum = 0;
		for (int x = 0; x < cameras.length; x++)
		{
			sum += cameras[x].getInventoryValue();
		}
		return sum;
	}
	



}

class DigitalCamera extends Camera
{


	int num;
	private String name;
	private String depo;
	int stock;
	int price;
	double valueOfInventory;
	double restockedInventory;
	double imageResolution;
	double rez;

	public DigitalCamera( String name, String depo, int num, int stock, int price, double valueOfInventory, double rez )
	{
		super( name, depo, num, stock, price, valueOfInventory, rez );
		this.name = name;
		this.depo = depo;
		this.num = num;
		this.stock = stock;
		this.price = price;
		calculateInventoryValue();
		this.rez = rez;

	}
		
	

	private void calculateInventoryValue()
	{
		inventoryValue = stockNum * unitPrice;
		restockedInventory = inventoryValue + (inventoryValue * .05);
	}
	
	public double getInventory()
	{
		return restockedInventory;
	}
	
	public void setImageResolution( double rez )
	{
		imageResolution = rez;
	}

	public double getImageResolution()
	{
		return rez;
	}
 
	public String toString()   
    	{   
        return ("Product Name: " + productName + "\n" + "Product Department: " + productDepo    
        + "\n" + "Amount in Stock: " + stockNum + "\n" + "Unit Price: " + unitPrice + "\n" + "Inventory Value: " + restockedInventory + "\n" + "Image Resolution: " + rez);   
    	}
}

[fred rosenberger]

In my honest opinion...

You should throw all this code away, and start over, the right way.

The first think you do is start without a computer. Pencil, paper, and erasers. You start by writing down what you want your code to do. You think about real properties of things. For example, a camera has a make, a model, and price. A camera doesn't have a department, or an inventoryValue.

A Store might have departments, and departments might have inventories...or the Store might have a inventory...

For what it is worth...I have written tons of code that once I got into it, I realized it wasn't right and ditched it all. Most developers will tell you the same thing.