New class not working

[Chris Haris]

Can anybody give me a hint as to why when I use :

public class DemoTV
{
  public static void main (String [] args)
  {
TVClass tv1,tv2;
tv1 = new TVClass ("Sony");
tv1.getbrand ("Sony");
tv1.getprice (1000.0);
tv1.getsize (52);
tv2 = new TVClass ("LG");
tv2.getbrand ("LG");
tv2.getprice (100.0);
tv2.getsize (9);
System.out.println (tv1.toString() ) ;
System.out.println (tv2.toString() ) ;
  }
}

for this class:

public class TVClass 
{
  private String brand;
  private double price;
  private double size;
  
  public TVClass (String brand)
{
  this.brand = brand;
  this.price = price;
  this.size = size;
}

public String getbrand (String brand)
{
  return this.brand;
}

public double getprice (double price)
{
  return this.price;
}

public double getsize (double size)
{
  return this.size;
}
}

it gives me:

> run DemoTV
TVClass@143724e
TVClass@749436
>

Am I missing something obvious? If I re run it multiple times, the numbers always come out differently too...

[John Jai]

If you want to print the brand, price and size, you have to call the getter methods using the TVClass object.

But still if you want to use the toString() then override the toString() method and just give the objects of the TVClass in the print statement.

But the getter methods do not confine to the standard specifications. And there is no setter method in first place to set the values.

[John Jai]

The TVClass shall look like below. I have put the constructor for you, but you can remove it and use the setter methods alone.

public class TvClass {
	private String brand;
	private double price;
	private double size;
	
	public TvClass(String brand, double price, double size) {
		this.brand = brand;
		this.price = price;
		this.size = size;
	}
	
	public String getBrand() {
		return brand;
	}
	public void setBrand(String brand) {
		this.brand = brand;
	}
	public double getPrice() {
		return price;
	}
	public void setPrice(double price) {
		this.price = price;
	}
	public double getSize() {
		return size;
	}
	public void setSize(double size) {
		this.size = size;
	}		
}

[Chris Haris]

wow thanks, I tried plugging it in to see what would happen though and got all this mess:

8 errors found:
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 8]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:8: cannot find symbol
symbol : constructor TVClass(java.lang.String)
location: class TVClass
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 9]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:9: getBrand() in TVClass cannot be applied to (java.lang.String)
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 10]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:10: getPrice() in TVClass cannot be applied to (double)
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 11]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:11: getSize() in TVClass cannot be applied to (int)
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 12]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:12: cannot find symbol
symbol : constructor TVClass(java.lang.String)
location: class TVClass
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 13]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:13: getBrand() in TVClass cannot be applied to (java.lang.String)
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 14]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:14: getPrice() in TVClass cannot be applied to (double)
File: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java [line: 15]
Error: C:\Users\Chris\Desktop\Java Programming Programs\java\DemoTV.java:15: getSize() in TVClass cannot be applied to (int)

Isn't it supposed to take the values I put in and print them back out?

[John Jai]

You have to match the number of parameters in the method with the number of arguments you pass while calling it.

In the DemoTV class check how you are many arguments you pass to the constructor. And while calling the geXXX method you don't need to pass any arguments.

[Chris Haris]

I figured out what I was doing wrong, but now I'm back to square one, its still giving me random values

[John Jai]

You could post both the class' code you have tried.

[John Jai]

TVClass@143724e - This is not a random value. Instead of giving tv1 in the print statement, try to give the getter such as tv1.getBrand(). I doubt if you have modified your TVClass in first place.

[Chris Haris]

I just did it with the one you gave me, if I tell it to print brand it works, but it won't print the whole thing out as a string, let me ask this, is it not going to? Am I trying to get java to do something it simply won't do?

[John Jai]

you can... see my first post about overriding the Object:toString() method of object.

Add the below method in the TvClass and try to print the object in the print statement.

@Override
public String toString() {
	return "Brand -> " + brand + " ... Price -> " + price + " ... Size -> " + size;
}

[Chris Haris]

Wow......................................... I knew to do that, I just totally spaced out... Thanks for saving me yet again John. Here's everything:

  public class TVClass {  
        private String brand;  
        private double price;  
        private double size;  
          
  public TVClass(String brand, double price, double size) {  
            this.brand = brand;  
            this.price = price;  
            this.size = size;  
        }  
          
  public String getBrand() 
        {  
            return brand;  
        }  
  
  public void setBrand(String brand) 
        {  
            this.brand = brand;  
        }  
  
  public double getPrice() {  
            return price;  
        }  
  
  public void setPrice(double price) 
        {  
            this.price = price;  
        }  
  
  public double getSize() 
        {  
            return size;  
        }  
  
  public void setSize(double size) 
        {  
            this.size = size;  
        }         
        
  @Override  

  public String toString() 
        {  
             return "The TV is a " + brand + " it costs " + price + " dollars" + " and is a " + size + " inch TV"; 
        }
  }

public class DemoTV
{
  public static void main (String [] args)
  {
TVClass tv1 = new TVClass ("Sony", 1200.0, 55);
System.out.println (tv1.toString());
TVClass tv2 = new TVClass ("LG", 700.0, 42);
System.out.println (tv2.toString());
if (tv1.equals(tv2))
  System.out.println ( "Both TVs are the same" );
else
  System.out.println ( "The TVs are not the same" );
  }
}

> run DemoTV
The TV is a Sony it costs 1200.0 dollars and is a 55.0 inch TV
The TV is a LG it costs 700.0 dollars and is a 42.0 inch TV
The TVs are not the same

[Chris Haris]

Chris Haris wrote:Wow......................................... I knew to do that, I just totally spaced out... Thanks for saving me yet again John. Here's everything:

  public class TVClass {  
        private String brand;  
        private double price;  
        private double size;  
          
  public TVClass(String brand, double price, double size) {  
            this.brand = brand;  
            this.price = price;  
            this.size = size;  
        }  
          
  public String getBrand() 
        {  
            return brand;  
        }  
  
  public void setBrand(String brand) 
        {  
            this.brand = brand;  
        }  
  
  public double getPrice() {  
            return price;  
        }  
  
  public void setPrice(double price) 
        {  
            this.price = price;  
        }  
  
  public double getSize() 
        {  
            return size;  
        }  
  
  public void setSize(double size) 
        {  
            this.size = size;  
        }         
        
  @Override  

  public String toString() 
        {  
             return "The TV is a " + brand + " it costs " + price + " dollars" + " and is a " + size + " inch TV"; 
        }
  }

public class DemoTV
{
  public static void main (String [] args)
  {
TVClass tv1 = new TVClass ("Sony", 1200.0, 55);
System.out.println (tv1.toString());
TVClass tv2 = new TVClass ("LG", 700.0, 42);
System.out.println (tv2.toString());
if (tv1.equals(tv2))
  System.out.println ( "Both TVs are the same" );
else
  System.out.println ( "The TVs are not the same" );
  }
}

> run DemoTV
The TV is a Sony it costs 1200.0 dollars and is a 55.0 inch TV
The TV is a LG it costs 700.0 dollars and is a 42.0 inch TV
The TVs are not the same

now just for fun, I changed size from a double to an int, because normally TVs are measured in whole inches... why doesn't line 9 like that? and how could I change it so it doesn't give me an error?

[John Jai]

By line #9 i believe you mean the constructor - if so you try to pass a double value from your demo class but try to store that in your size variable declared as int in TvClass.

If you change a type, you have to change the type also in affected constructors and the methods.

[Chris Haris]

Oh ok, that makes sense. Thanks a lot I appreciate it.

[Chandan Sarma]

Hi ,

you need to modified your getter and setter method some what and as for my understand no need of constructor is there.

package demo;

    
    class TVClass   
    {  
      private String brand;  
      private double price;  
      private double size;

    public String getBrand() {
        return brand;
    }

    public double getPrice() {
        return price;
    }

    public double getSize() {
        return size;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public void setSize(double size) {
        this.size = size;
    }
        
   
      
 
    }  
   public class DemoTV  
    {  
      public static void main (String [] args)  
      {  
    TVClass tv1,tv2;  
    tv1 = new TVClass ();  
    tv1.setBrand("Sony");  
    tv1.setPrice(1000.0);  
    tv1.setSize(52);  
    tv2 = new TVClass ();  
    tv2.setBrand("LG");  
    tv2.setPrice(100.0);  
    tv2.setSize(9);  
    System.out.println ("the brand is"+tv1.getBrand()) ;  
    System.out.println ("the size is"+tv2.getSize() ) ;  
      }  
    }  

Using this you are able to print any thing what you want. i am printing the tv1 "brand " and tv2 "size"

the Out put is given as follow

compile-single:
run-main:
the brand isSony
the size is9.0