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How to extract from a vector and add them to another vector?

Posted on 2003-12-06
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Last Modified: 2010-03-31

Hi every one..
Could you please help me with my question..

-I have a class called Customer which has four variables (int id, String name, String city, String phone)

- I have another class called TestCustomer that has a main method..


Now in this class I have to:

1- create five customers and add them to a vector called "Customers"

2- create another Vector called "CustomerNames" and extract the 5 customers' names from the "Customers" vector and add them to the "CustomerNames" vectors..


My questions are:

1- when I create the five customers do I have to specify the values of the attributes?

2- How can I extract from a vector and add it to another one..


thanks in advance,,
waiting for your answers
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Question by:SEstudent
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CEHJ earned 155 total points
ID: 9888821
>>1- when I create the five customers do I have to specify the values of the attributes?

Usually, yes and it's good to do so where possible.

>>2- How can I extract from a vector and add it to another one..

Iterate the Customers vector and add to the customer names one

Iterator iter = customers.iterator();
while(iter.hasNext()) {
   Customer cust = (Customer)iter.next();
   customerNames.add(cust.getName());
}

Note that Customer should have a getName method that returns a String. The 'customerNames' variable in the example is your other Vector

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Expert Comment

by:CEHJ
ID: 9888828
...and of course 'customers' is the Vector of Customer
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Author Comment

by:SEstudent
ID: 9888890


thanks alot for your help,,now it work but I want to ensure that it is working in the right way


now will this be OK


=========

import javax.swing.*;
import java.util.*;

public class TestCustomer {
  public static void main(String[] args) {
    Customer c1, c2, c3, c4, c5;
    Vector customers = new Vector();
    Vector customerNames = new Vector();
    c1 = new Customer(678, "John", "Dubai", "7658888");
    c2 = new Customer(888, "Bill", "Sharjah", "8879990");
    c3 = new Customer(223, "Ed", "Al-Ain", "7455668");
    c4 = new Customer(459, "Steve", "Abu Dhabi", "7763454");
    c5 = new Customer(142, "Harry", "RAK", "6678333");
    customers.add(c1);
    customers.add(c2);
    customers.add(c3);
    customers.add(c4);
    customers.add(c5);

    Iterator iter = customers.iterator();
while(iter.hasNext()) {
   Customer cust = (Customer)iter.next();
   customerNames.add(cust.getName());
}

 JOptionPane.showMessageDialog(null, "vector v: \n" +       customers.toString());
 JOptionPane.showMessageDialog(null, "vector vn: \n" +       customerNames.toString());

=================
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Expert Comment

by:CEHJ
ID: 9888913
That's OK. Of course, unless there's some specific reason for keeping those Customer references, you can do:

customers.add(new Customer(678, "John", "Dubai", "7658888"));

etc.
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Author Comment

by:SEstudent
ID: 9888944

oh,,thanks alot..sorry for disturbing you..
but I have another question..

the last point (after creating another vector called CustomerID)  is that I have to move all the work to a method called "CreateCustomers" and call this method from the main method..could you please help me with that?
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LVL 86

Expert Comment

by:CEHJ
ID: 9888968
OK - but you must do your assignment yourself after this ;-)


In main:

TestCustomer tc = new TestCustomer();
tc.createCustomers();

...
// constructor

public TestCustomer() {
  customerNames = new Vector();
  customerIds = new Vector();
  customers = new Vector();
}

public void createCustomers() {
  // fill the Vectors
}
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Author Comment

by:SEstudent
ID: 9888983

this helped alot,,

thanks alot :)
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Expert Comment

by:monkesdb
ID: 9888991
you really want the customers customerNames and customerIDs to be member variables

TestCustomer {

    Vector customers = new Vector();
    Vector customerNames  = new Vector();
    Vector customerIDs = new Vector();


//you then want to use these in your method...

    private void CreateCustomers(/* pass in anything you use to create the data */)
    {
        //put your code in here
    }

    public static void main(String args[])
    {
         CreateCustomers();
    }

}
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Expert Comment

by:monkesdb
ID: 9889013
if you want the CreateCustomers method to be inside a different class you will need to pass the Vectors into it as parameters.
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LVL 86

Expert Comment

by:CEHJ
ID: 9889055
8-)

Incidentally, method and variable names should start with a small letter, class name with a capital
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