I have the following class as a example to a similar problem im having ...

Class Car

code:

public class Car {
        private String name;
        public Car(String name) {
            this.name = name;
        }
        public String getName() {
            return name;
        } 
    }

Class CreateCarFromList

code:

public class CreateCarFromList {
        private List carNames = new ArrayList();
        private List carObject = new ArrayList();
        /** Creates a new instance of CreateCarFromList */
        public CreateCarFromList() {
           carNames.add("Red");
           carNames.add("Blue");
           carNames.add("Yellow");
           
           Iterator it = carNames.iterator();
           while (it.hasNext()) {
               Car x = new Car((String) it.next());
               carObject.add(x);
           }
        }
    }

in the last class i have an arraylist,carNames, with the following value
["Red", "Blue", "Yellow"]

than i do an iteration and create an instance of an object in each iteration and add it to another arraylist, carObject

my problem is what do i need to do, to add to the Car class or perhaps to CreateCarFromList Class.

so that i can say for a

String s = "Red";

give me from carObject list the Car object that has that attribute. (hope this make sense)

--------------------

FD

Nope, I don't get you.

Are you trying to create an array of objects.

E.g you have an array of Car objects.

Where the object Car can have the attributes, say Colour, and model:

class Car
{
   String Colour;
   String Make;

Once you work with this kind of basic structure, everything else should fall into place right? No matter what you are doing.


For example here's an example:

class Car
{
  private String colour;
  private String make;

  //----------------------------------------------------------

  public Car(String c, String m)
  { 
   // constructor
   colour = c;
   make = m;

  }
//----------------------------------------------------------

  public void displayCar()
  {
  System.out.print(" Colour: " + colour);
  System.out.print(", Make: " + make);
  System.out.print("\n");
  }
  //----------------------------------------------------------

  public String getColour() // get last name
  { 
    return colour; 
  }

  public String getMake()
  {
    return make;
    
  }
} // end class Car




class ArrayInOb
{
   private Car[] a; // ref to array a
   private int nElems; // number of data items

//-------------------------------------------------------------

   public ArrayInOb(int max) // constructor
   {
    a = new Car[max]; // create the array
    nElems = 0; // no items yet
   }
  //-------------------------------------------------------------

  // put car into array
  public void insert(String last, String first)
  {
  a[nElems] = new Car(last, first);
  nElems++; // increment size
  }
 //-------------------------------------------------------------

  public void display() // displays array contents
  {
  for(int j=0; j<nElems; j++) // for each element,
   a[j].displayCar(); // display it
   System.out.println("");
  }


public void insertionSort()
{
int in, out;
for(out=1; out<nElems; out++) // out is dividing line
{
  Car temp = a[out]; // remove marked car
  in = out; // start shifting at out
  while(in>0 && // until smaller one found,

  a[in-1].getMake().compareTo(temp.getMake())>0)
  {
  a[in] = a[in-1]; // shift item to the right
   --in; // go left one position
  }
  a[in] = temp; // insert marked item
  } // end for
} // end insertionSort()


} // end class ArrayInOb
class CarList
{
  public static void main(String[] args)
  {
   int maxSize = 100; // array size
   ArrayInOb arr; // reference to array
   arr = new ArrayInOb(maxSize); // create the array

   //assign values here, the example is hard
   //coded but you can just extract them from an array
   //or text file

   arr.insert("Blue", "Ford");
   arr.insert("Red", "Toyota");
   arr.insert("Aqua", "Limo");
   arr.insert("Black", "Jaguar");
   arr.insert("White", "BMW");

   System.out.println("Before sorting:");
   arr.display(); // display items
   arr.insertionSort(); // insertion-sort them by make
   System.out.println("After sorting by make:");
   arr.display(); // display them again
   } // end main()
} // end class ObjectSortApp

it was quite simple actually, with the use of HashMap instead of an ArrayList to put the car object in (key: "car colour", value: car object)

This article has been dead for over six months. Start a new discussion instead.