AKMA’s Random Thoughts

It's a good movie, I hope you can see it.

You probably cut yourself on the dishmatique -- better lay off the fancy dishwashing gadgets and use a nice soft sponge.

Did you do damage to your digit doing dishes in the dishmatique due to a desire to outdo Derrida?

(sorry - feeling like a little aliteration)

Indubitably!

Hey, AKMA! Just looking at your weblog to see how easy it is to make a comment. (Pretty easy!) OK to delete this if you don't want it cluttering up your discourse! Peace. -LH

A variable leads a simple life, full of activity but quite short (measured in nanoseconds, usually). It all begins when the program finds a variable declaration, and a variable is born into the world of the executing program. There are two possible places where the variable might live, but we will venture into that a little later.

Each Stack Frame represents a function. The bottom frame is always the main function, and the frames above it are the other functions that main calls. At any given time, the stack can show you the path your code has taken to get to where it is. The top frame represents the function the code is currently executing, and the frame below it is the function that called the current function, and the frame below that represents the function that called the function that called the current function, and so on all the way down to main, which is the starting point of any C program.

That gives us a pretty good starting point to understand a lot more about variables, and that's what we'll be examining next lesson. Those new variable types I promised last lesson will finally make an appearance, and we'll examine a few concepts that we'll use to organize our data into more meaningful structures, a sort of precursor to the objects that Cocoa works with. And we'll delve a little bit more into the fun things we can do by looking at those ever-present bits in a few new ways.

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:

To address this issue, we turn to the second place to put variables, which is called the Heap. If you think of the Stack as a high-rise apartment building somewhere, variables as tenets and each level building atop the one before it, then the Heap is the suburban sprawl, every citizen finding a space for herself, each lot a different size and locations that can't be readily predictable. For all the simplicity offered by the Stack, the Heap seems positively chaotic, but the reality is that each just obeys its own rules.