ArrayList Help

Please support our Java advertiser: Programming Forums - DaniWeb Sister Site
Thread Solved

Join Date: Apr 2007
Posts: 4
Reputation: 2mdennis is an unknown quantity at this point 
Solved Threads: 0
2mdennis 2mdennis is offline Offline
Newbie Poster

ArrayList Help

 
0
  #1
Apr 13th, 2007
I am fairly new to Java and am having some difficulty with implementing an arraylist.

I have some classes that contain variables and i have a new class that contains my arraylist. I would like to know how i would get the variables from the other classes into the arraylist in the new class. I know that you would use the add methods, but am unsure of the code to do it.

Example code would be very useful.

Thanks
Reply With Quote Quick reply to this message  
Join Date: Aug 2005
Posts: 5,266
Reputation: iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold iamthwee is a splendid one to behold 
Solved Threads: 377
Featured Poster
iamthwee's Avatar
iamthwee iamthwee is offline Offline
Posting Expert

Re: ArrayList Help

 
0
  #2
Apr 13th, 2007
You should just be able to add custom objects into your arrayList as you would say strings etc.
*Voted best profile in the world*
Reply With Quote Quick reply to this message  
Join Date: Jun 2006
Posts: 7,619
Reputation: ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of ~s.o.s~ has much to be proud of 
Solved Threads: 468
Super Moderator
Featured Poster
~s.o.s~'s Avatar
~s.o.s~ ~s.o.s~ is offline Offline
Failure as a human

Re: ArrayList Help

 
0
  #3
Apr 14th, 2007
I don't accept change; I don't deserve to live.
Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: arunjain_in is an unknown quantity at this point 
Solved Threads: 1
arunjain_in arunjain_in is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #4
Apr 14th, 2007
Hi,
if i have got your problem write....this can be the solution.

I have 2 classes A and B and I am adding its variable to arraylist in third class. Take care of access modifiers. Also objects can be added to arraylist like wrapper, string or custom objects along with primitive variables.
<----Array List class----->
import java.util.ArrayList;

publicclass arraylisttest {

public static void main(String[] args) {
ArrayList al = new ArrayList();
A a = new A();
B b = new B();
al.add(A.i);
al.add(B.d);
al.add(A.ii);

}

}

<----Class A---->
publicclass A{
public int ii;
public Integer i;
}

<-----Class B----->
publicclass B{

public Double d;
}


Originally Posted by 2mdennis View Post
I am fairly new to Java and am having some difficulty with implementing an arraylist.

I have some classes that contain variables and i have a new class that contains my arraylist. I would like to know how i would get the variables from the other classes into the arraylist in the new class. I know that you would use the add methods, but am unsure of the code to do it.

Example code would be very useful.

Thanks
Last edited by arunjain_in; Apr 14th, 2007 at 12:30 am.
Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: 2mdennis is an unknown quantity at this point 
Solved Threads: 0
2mdennis 2mdennis is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #5
Apr 14th, 2007
Thanks for the Help.

However i forgot to mention that the classes that contain the variables, are in constructors. And now i am getting errors saying 'cannot find symbol - constructor classA'. What can i do to overcome this error.

Thanks
Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: arunjain_in is an unknown quantity at this point 
Solved Threads: 1
arunjain_in arunjain_in is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #6
Apr 14th, 2007
can u plz send me your code....then i may be able to help you better...
Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: 2mdennis is an unknown quantity at this point 
Solved Threads: 0
2mdennis 2mdennis is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #7
Apr 14th, 2007
HI, this is the code for my first class, which contains the variables and constructor. Then i have several other classes that contain the same kind of code:

import java.util.Scanner;

public class Details
{
Scanner console = new Scanner(System.in);

public String name;
public int age;

public Details(String Name, int Age)
{
name = Name;
age = Age;
}

public String getname()
{
return name;
}

public int getage()
{
return age;
}

Then i have the class that contains the arraylist:

import java.util.ArrayList;

public class arrayList
{
public static void main(String[] args)
{
List<Details> list = new ArrayList<Details>();

Details a = new Details();
list.add(Details.name);
list.add(Details.age);

System.out.println(list);
}
}
Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: arunjain_in is an unknown quantity at this point 
Solved Threads: 1
arunjain_in arunjain_in is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #8
Apr 14th, 2007
try this.....actually the problem was....u were instantiating ur Details classes with passing any argument and in your Details clas u didnt had any such constructor defined.....now i hope this will work fine.

import java.util.Scanner;

public class Details {
Details(){

}
Scanner console = new Scanner(System.in);

public String name;

public int age;

public Details(String Name, int Age) {
name = Name;
age = Age;
}

public String getname() {
return name;
}

public int getage() {
return age;
}
}


import java.util.ArrayList;
import java.util.List;

public class arrayList
{
public static void main(String[] args)
{
List list = new ArrayList();

Details a = new Details();
list.add(a.name);
list.add(a.age);

System.out.println(list);
}
}


Reply With Quote Quick reply to this message  
Join Date: Apr 2007
Posts: 4
Reputation: 2mdennis is an unknown quantity at this point 
Solved Threads: 0
2mdennis 2mdennis is offline Offline
Newbie Poster

Re: ArrayList Help

 
0
  #9
Apr 15th, 2007
Thanks for the Help, have got it working now.
Reply With Quote Quick reply to this message  
Reply

This thread has been marked solved.
Perhaps start a new thread instead?
Message:


Thread Tools Search this Thread



About Us | Contact Us | Advertise | DaniWeb | Acceptable Use Policy | RSS Feed

©2003 - 2009 DaniWeb® LLC