Differences between C++ and Java with this-pointer

"Rasti" <me*********@dbforums.com> wrote...

I am trying to translate a C++ script to Java. Are there any differences
between the C++ this-pointer and the Java this-pointer?

In Java 'this' is NOT a pointer. There are no pointers in Java.

And, if you have questions on Java, try a Java newsgroup.

Victor

"Victor Bazarov" <v.********@comAcast.net> wrote in message
news:28cqb.114745$e01.418754@attbi_s02...

"Rasti" <me*********@dbforums.com> wrote...

I am trying to translate a C++ script to Java. Are there any differences
between the C++ this-pointer and the Java this-pointer?

In Java 'this' is NOT a pointer. There are no pointers in Java.

And, if you have questions on Java, try a Java newsgroup.

Personally, I think that a question about the similarities and
differences between C++ and Java is on-topic for either C++ or Java
newsgroups. To answer the OP's question, in C++ 'this' is a pointer and in
Java 'this' is a reference, because Java doesn't have pointers. However,
the C++ 'this' pointer is rather strange, because it cannot be reassigned
and cannot be null. It probably should have been a reference. As I
understand it, the main reason it wasn't is because it was invented before
references were.

Joe Gottman

Joe Gottman wrote:

However,
the C++ 'this' pointer is rather strange, because it cannot be reassigned
and cannot be null.

void func(A& a);
A* aptr = 0;
func(*aptr);

I think you'll find that within func a's this pointer will
be null.

Victor Bazarov wrote:

"Rasti" <me*********@dbforums.com> wrote...

I am trying to translate a C++ script to Java. Are there any differences
between the C++ this-pointer and the Java this-pointer?

In Java 'this' is NOT a pointer. There are no pointers in Java.

There are no pointers, but there is a NullPointerException.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)

"lilburne" <li******@godzilla.net> wrote in message
news:bo*************@ID-203936.news.uni-berlin.de...

Joe Gottman wrote:

However,
the C++ 'this' pointer is rather strange, because it cannot be reassigned and cannot be null.

void func(A& a);
A* aptr = 0;
func(*aptr);

I think you'll find that within func a's this pointer will
be null.

Derefencing a null pointer, as you do when you call func(*aptr) results
in undefined behavior. You might have a's this pointer null inside the
function call, or you might have a core dump before func is even called.

Joe Gottman