RDFWeb and Friend of a Friend (FOAF): Wobbly

February 13, 2003

Wobbly

The front page of rdfweb.org is somewhat wobbly this week. I'm in the middle of moving it across to use the Movable Type weblog, instead of hand-coded HTML. Sorry things are a bit rough. We're getting there slowly!

Posted by danbri at February 13, 2003 10:41 PM

Comments

Thanks!

Posted by: Teneriffa Flüge on January 17, 2004 01:06 PM

These secret identities serve a variety of purposes, and they help us to understand how variables work. In this lesson, we'll be writing a little less code than we've done in previous articles, but we'll be taking a detailed look at how variables live and work.

Posted by: Chroseus on January 20, 2004 07:30 AM

When a variable is finished with it's work, it does not go into retirement, and it is never mentioned again. Variables simply cease to exist, and the thirty-two bits of data that they held is released, so that some other variable may later use them.

Posted by: Didimus on January 20, 2004 07:30 AM

Posted by: Arnold on January 20, 2004 07:30 AM

Note first that favoriteNumbers type changed. Instead of our familiar int, we're now using int*. The asterisk here is an operator, which is often called the "star operator". You will remember that we also use an asterisk as a sign for multiplication. The positioning of the asterisk changes its meaning. This operator effectively means "this is a pointer". Here it says that favoriteNumber will be not an int but a pointer to an int. And instead of simply going on to say what we're putting in that int, we have to take an extra step and create the space, which is what does. This function takes an argument that specifies how much space you need and then returns a pointer to that space. We've passed it the result of another function, , which we pass int, a type. In reality, is a macro, but for now we don't have to care: all we need to know is that it tells us the size of whatever we gave it, in this case an int. So when is done, it gives us an address in the heap where we can put an integer. It is important to remember that the data is stored in the heap, while the address of that data is stored in a pointer on the stack.

Posted by: Jordan on January 20, 2004 07:31 AM

The Stack is just what it sounds like: a tower of things that starts at the bottom and builds upward as it goes. In our case, the things in the stack are called "Stack Frames" or just "frames". We start with one stack frame at the very bottom, and we build up from there.

Posted by: Reginald on January 20, 2004 07:31 AM

Posted by: Brian on January 20, 2004 07:31 AM

Seth Roby graduated in May of 2003 with a double major in English and Computer Science, the Macintosh part of a three-person Macintosh, Linux, and Windows graduating triumvirate.

Posted by: Lucy on January 20, 2004 07:31 AM

Seth Roby graduated in May of 2003 with a double major in English and Computer Science, the Macintosh part of a three-person Macintosh, Linux, and Windows graduating triumvirate.

Posted by: Justinian on January 20, 2004 07:31 AM

Since the Heap has no definite rules as to where it will create space for you, there must be some way of figuring out where your new space is. And the answer is, simply enough, addressing. When you create new space in the heap to hold your data, you get back an address that tells you where your new space is, so your bits can move in. This address is called a Pointer, and it's really just a hexadecimal number that points to a location in the heap. Since it's really just a number, it can be stored quite nicely into a variable.

Posted by: Laura on January 20, 2004 07:31 AM

Let's see an example by converting our favoriteNumber variable from a stack variable to a heap variable. The first thing we'll do is find the project we've been working on and open it up in Project Builder. In the file, we'll start right at the top and work our way down. Under the line:

Posted by: Pompey on January 20, 2004 07:31 AM

Hello, I just wanted to say you have a very informative site which really made me think, Thanks !
ent site with a wealth of info.!...thanks very much!

Posted by: endrew on January 22, 2004 07:39 AM

Hi! You did a nice job on creating
this website! Good stuff! Keep it up! See you!:-)
Keep up this great resource.

Posted by: klemens on January 22, 2004 07:41 AM

sms sprüche

Posted by: handylogos on January 22, 2004 01:32 PM

sms sprüche

Posted by: handylogos on January 22, 2004 01:33 PM

Posted by: rgerhgrt on January 24, 2004 04:26 PM