Java Answers Forum - Help With Using Java Pointers/Reference Variables

Articles |
News |
Weblogs |
Books |
Forums

Artima Forums | Articles | Weblogs | Java Answers | News

Sponsored Link •

Java Answers Forum
Help With Using Java Pointers/Reference Variables

3 replies on 1 page. Most recent reply: Jun 10, 2005 8:38 AM by ziyuan

Welcome Guest
Sign In

Back to Topic List

Reply to this Topic

Search Forum

Threaded View


Previous Topic		Next Topic

Flat View: This topic has 3 replies on 1 page

andy

Posts: 6
Nickname: chant9
Registered: Mar, 2005

Help With Using Java Pointers/Reference Variables

Posted: Mar 29, 2005 11:28 AM

Hi im trying to implement a type of pointer but i cant work out how to do it. I found some code that seemed to suggest that it was something like below, but it doesnt work.

int x =10;
int y = new int(x);

Then when altering y, x would also be altered.

If anyone knows how this is done please let me know.

Thanks

Justin

Posts: 1
Nickname: zallambo
Registered: Jun, 2005

Re: Help With Using Java Pointers/Reference Variables

Posted: Jun 9, 2005 6:12 PM

Someone correct me if I'm wrong, but there is absolutely no way to create a pointer to any primitive data type or function in Java. One can create an Integer object, and assign it a value, but it doesn't work exactly like an int, and cannot reference an int. I am switching to C++ on a current programming project because of Java's lack of pointers.

Matthias Neumair

Posts: 660
Nickname: neumi
Registered: Sep, 2003

Re: Help With Using Java Pointers/Reference Variables

Posted: Jun 9, 2005 11:00 PM

i = 14 would change i, not the content of the space in memory where the value of i is located. Therefore it would be against the rules of object oriented programming.
C++ does SUPPORT object oriented programming, but it's not an object oriented language

There are 2 solutions for this problem.

1. The simple way: use a array with length 1.
a = new int[]{10};
b = a;
altering a[0] will also change b[0]
This solution works, but it's not the way you should do it.

2. The object oriented way: create a class storing a int value

public class MyInteger{
  public MyInteger() {
    this(0);
  }
  public MyInteger(int val) {
    iVal = val;
  }
  public int get() {
    return iVal;
  }
  public void set(int newValue) {
    iVal = newValue;
  }
  private int iVal;
}

That would be the way it should be done if you really want to program following the rules of object oriented languages.

Try programming in SmallTalk. SmallTalk absolutely offers no way to alter a variable from the outside. You can only tell the variable to alter itself in a defined way.
This language really is for hard core programmers.

ziyuan

Posts: 2
Nickname: ziyuan
Registered: Jun, 2005

Re: Help With Using Java Pointers/Reference Variables

Posted: Jun 10, 2005 8:38 AM

Yes! Java has not pointer,but you can use a mechanism similar pointer(called "reference itself of class").

You can refer to the book that named "data structure in Java"(may be).

Now,i get you example:

class Node{
private int data;
private Node next; // reference Node class itself

Note(int d){
/* method body */
}
}

Flat View: This topic has 3 replies on 1 page

Previous Topic

Next Topic


	Web Artima.com