Core Java - What's the difference between Object and "E"?

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Core Java | Question 488 of 502

What's the difference between Object and "E"?

I'm trying to write an Iterator class for a LinkedList class that I wrote.
One of the methods is "public E next()"
I try to return an "E" but eclipse says "cannot convert from Object to E".
How do I fix this?

Total Answers and Comments: 4

Last Update: February 06, 2009 Asked by: esekiel

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Best Rated Answer

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Submitted by: ravikishore_gvr

Object is a class where as E is nothing but Generic Argument, While writing Generic Classes we will use type E.

Above answer was rated as good by the following members:
er.mukesh_208, abhijitp

July 15, 2008 01:08:34

srinivasa123

Member Since: July 2008 Contribution: 1

RE: What's the difference between Object and "E"?

change the method name as next1() it wil work.

Is this answer useful? Yes | No

July 16, 2008 02:54:33

ravikishore_gvr

Member Since: July 2008 Contribution: 1

RE: What's the difference between Object and "E"?

Object is a class where as E is nothing but Generic Argument While writing Generic Classes we will use type E.

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1 0

Overall Rating: +1

August 05, 2008 06:05:11

shishir11485

Member Since: August 2008 Contribution: 1

RE: What's the difference between Object and "E"?

Object having a reference of one variable store in stack whereas "E" is created in a heap don't have a reference variable

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0 3

Overall Rating: -3

February 06, 2009 16:19:59

kabir soni

Member Since: February 2009 Contribution: 3

RE: What's the difference between Object and "E"?

Object is a class and E is a generic type parameter . And Iterator class alwayes return Object so to fix this problem you need to call it. For example

import java.util.ArrayList;

import java.util.Iterator;

class list {

ArrayList list new ArrayList();

public E next() {

Iterator i list.iterator();

return (E)i.next();

}

public class TestProgram {

public static void main(String[] args) {

list list new list();

list.list.add( A );

System.out.println(list.next());

}

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