Groups > comp.lang.java.programmer > #5190

Re: What's the difference between and instance and an object?

Path	csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!news.linkpendium.com!news.linkpendium.com!news.glorb.com!postnews.google.com!l2g2000prg.googlegroups.com!not-for-mail
From	Lewis Bloch <lewisbloch@google.com>
Newsgroups	comp.lang.java.programmer, comp.lang.java.help
Subject	Re: What's the difference between and instance and an object?
Date	Fri, 10 Jun 2011 11:05:16 -0700 (PDT)
Organization	http://groups.google.com
Lines	37
Message-ID	<be2152be-fdfc-4826-bf4c-0b9899d2818f@l2g2000prg.googlegroups.com> (permalink)
References	<5d84ac2b-e81b-4c40-b3e3-c7248f1d7298@r35g2000prj.googlegroups.com> <4decfdbc$0$17721$426a74cc@news.free.fr> <1a327de4-8451-4379-a75b-7cc2dab3fb5b@34g2000pru.googlegroups.com>
NNTP-Posting-Host	127.6.6.6
Mime-Version	1.0
Content-Type	text/plain; charset=ISO-8859-1
Content-Transfer-Encoding	quoted-printable
X-Trace	posting.google.com 1307729117 28670 127.0.0.1 (10 Jun 2011 18:05:17 GMT)
X-Complaints-To	groups-abuse@google.com
NNTP-Posting-Date	Fri, 10 Jun 2011 18:05:17 +0000 (UTC)
Complaints-To	groups-abuse@google.com
Injection-Info	l2g2000prg.googlegroups.com; posting-host=127.6.6.6; posting-account=6gJCewoAAAATGk_BiH9Eo-1pkyAWegc7
User-Agent	G2/1.0
X-Google-Web-Client	true
X-Google-Header-Order	ASELCHRU
X-HTTP-UserAgent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/534.30 (KHTML, like Gecko) Chrome/12.0.742.91 Safari/534.30,gzip(gfe)
Xref	x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:5190 comp.lang.java.help:761

Cross-posted to 2 groups.

Show key headers only | View raw

On Jun 6, 9:33 am, Chad <cdal...@gmail.com> wrote:
> On Jun 6, 9:18 am, Patrick <patr...@antispam.invalid> wrote:
>
> > Le 06/06/2011 18:08, Chad a écrit :
>
> > > How can there be an instance of MyStack when I never made a
> > > constructor for it? That is, I never create a MyStack object.
>
> > You always have a constructor, even if implicit.
> > You created an instance with new MyStack().
>
> Maybe I'm acting like a dweeb about this, but according to the Java
> Docs, when there is no explicit constructor, then the implict
> constructor is Object. I think that is how they say it. So I figured

That is not correct.  I know of no place in any of the standard API's
Javadocs that make any statement that could be understood that way.  I
don't even know where in the Javadocs you would hope to find such a
statement.

> that when I created instance of MyStack with 'new MyStack()', that the
> only instance would be Object since I omitted the MyStack constructor.

No.

When you omit an explicit constructor, one *for that very type* is
provided by the compiler, so the implicit constructor in your case is
'public MyStack()'.

"All classes have at least one constructor. If a class does not
explicitly declare any, the Java compiler automatically provides a no-
argument constructor, called the default constructor."
<http://download.oracle.com/javase/tutorial/java/javaOO/
objectcreation.html>

--
Lew

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Find similar

Thread

What's the difference between and instance and an object? Chad <cdalten@gmail.com> - 2011-06-06 09:08 -0700
  Re: What's the difference between an instance and an object? Chad <cdalten@gmail.com> - 2011-06-06 09:16 -0700
  Re: What's the difference between and instance and an object? Patrick <patrick@antispam.invalid> - 2011-06-06 18:18 +0200
    Re: What's the difference between and instance and an object? Chad <cdalten@gmail.com> - 2011-06-06 09:33 -0700
      Re: What's the difference between and instance and an object? Mayeul <mayeul.marguet@free.fr> - 2011-06-06 18:54 +0200
        Re: What's the difference between and instance and an object? Chad <cdalten@gmail.com> - 2011-06-06 10:11 -0700
        Re: What's the difference between and instance and an object? Abu Yahya <abu_yahya@invalid.com> - 2011-06-08 21:21 +0530
          Re: What's the difference between and instance and an object? Abu Yahya <abu_yahya@invalid.com> - 2011-06-08 21:24 +0530
            Re: What's the difference between and instance and an object? Patricia Shanahan <pats@acm.org> - 2011-06-08 09:33 -0700
              Re: What's the difference between and instance and an object? Abu Yahya <abu_yahya@invalid.com> - 2011-06-08 22:07 +0530
          Re: What's the difference between and instance and an object? Lewis Bloch <lewisbloch@google.com> - 2011-06-10 11:06 -0700
            Re: What's the difference between and instance and an object? Abu Yahya <abu_yahya@invalid.com> - 2011-06-11 23:58 +0530
      Re: What's the difference between and instance and an object? Lewis Bloch <lewisbloch@google.com> - 2011-06-10 11:05 -0700

csiph-web