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Thread: Edit ArrayList Object

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    Default Edit ArrayList Object

    Deleted since my college will scan using turnitin.com
    Last edited by frankycool; November 16th, 2009 at 11:57 AM. Reason: Plagarism


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    Default Re: Edit ArrayList Object

    I suspect it may be because you have the variable that holds the inventory declared static inside of CarsSubProduct. Change it to be non-static, and then you can get the object reference using the ArrayList.get() method:

    CarsSubProduct car = products.get(0); // get the first car in the list
    car.soldOne(); // decrement the inventory of car by one

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    Default Re: Edit ArrayList Object

    Thanks,i tried your method and now i can specify which object i want to get in the array like


    int price=Cars.get(0).getprice();

    But now i want to search all the indexes and get the index which contains for example Ford_Mustang then i use another syntax as such above to get the price

    Cars.add( new CarMethods( "Ford_Mustang",1,1000,10000 ) );

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    Default Re: Edit ArrayList Object

    Override the equals method of your CarsSubProduct class (or whatever you are putting into the ArrayList) so that it will test equality by the name:

    public boolean equals(Object o)
    {
         if (o instanceof String)
         {
              return (this.name.equals(o.toString());
         }
         else
         {
              return false;
         }
    }

    Then assuming each ArrayList you have will only have 1 Ford_Mustang, you can use the indexOf method to find it:

    int index = car.indexOf("Ford_Mustang");

  5. The Following User Says Thank You to helloworld922 For This Useful Post:

    frankycool (November 15th, 2009)

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    Default Re: Edit ArrayList Object

    Thanks will do as explained

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    Default Re: Edit ArrayList Object

    indexOf returns -1 if it doesn't find the object you want.

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    Default Re: Edit ArrayList Object

    Even when i initialize Carname and run on netbeans debugger,Carname still appears as null

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    Default Re: Edit ArrayList Object

    Post your CarName class... I have a feeling the error is somewhere in there.

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    Default Re: Edit ArrayList Object

    I need the CarMethods class. Could you post that as well?

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    Default Re: Edit ArrayList Object

    Deleted since my college will scan using turnitin.com
    Last edited by frankycool; November 16th, 2009 at 11:45 AM. Reason: Plagarism

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    Default Re: Edit ArrayList Object

    You forgot to over-write the the equals method in the CarMethods class

    public boolean equals(Object o)
    {
         if (o instanceof String)
         {
              return (this.name.equals(o.toString());
         }
         else
         {
              return false;
         }
    }

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    Default Re: Edit ArrayList Object

    Deleted since my college will scan using turnitin.com
    Last edited by frankycool; November 16th, 2009 at 11:46 AM. Reason: Plagarism

  14. #13
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    Default Re: Edit ArrayList Object

    hmm.. it seems that the indexOf method compares the types first (kind of annoying )

    An easy way around this is to create a "dummy" CarMethods object that has the name, but nothing else.

    So:

    Cars.indexOf(new CarMethods("Ford_Mustang",0,0,0));

    You'll also need to change the .equals() method to this:

    	public boolean equals(Object o)
    	{
    		if (o instanceof String)
    		{
    			return (this.carsnames.equals(o));
    		}
     
    		else if (o instanceof CarMethods)
    		{
    			return (this.carsnames.equals(((CarMethods) o).carsnames));
    		}
    		else
    		{
    			return false;
    		}
    	}
    will give you the indexOf the first Ford_Mustang in the ArrayList. The alternative is to iterate through the entire ArrayList of Cars, which isn't too hard.

    public int customIndexOf(ArrayList<CarMethods> cars, String toFind)
    {
         for (int i = 0; i < cars.size(); i++)
         {
              if (cars.get(i).equals(toFind))
               {
                   return i;
              }
         }
         return -1;
    }

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