[Twisted29]

Lin, the asterik specifies a pointer. A pointer is a location in computer memory. It allows you not only to use then pointer value, but that data stored in that value. Actually, you can interept THAT data as a pointer and that THAT data as a pointer and you end up with nice things like stacks and trees. Good way to link data. Its also faster than passing values.

As far as programming a TI-83, they run off of a Motorola 68000 16-bit ASM. I have one too I've started making some cool stuff for it, maybe you can help me out with some of the linking interfaces? Any idea what ports are use for data transfer vs. handshaking?

[Lin Sivvi Defiant Hero]

You lost me, right after the first few words Can you tell me a little more general idea of what it does to a variable compared to not having it with a variable?

[CyC0Dad]

The * says the variable is a pointer (contains the address of the value and not the value)

The & is used to define "The address of" so in this case I belive he is trying to define a variable that is of type pointer to store the address of "SomeVariable" to show how you can change the value of a variable via a pointer.

[Lin Sivvi Defiant Hero]

I now understand kind of. Thank you guys.

[Warhammer]

In the simplest programming terms, here's what * and & are for (and other stuff like data types)..

All programs are simply sets of instructions executed in computer memory. Assume that the beginning of the program starts at "address 0" and goes up from there. When you declare a variable, via "int", "char", etc. you are setting up a chunk of memory for a particular purpose. If it's an "int" type (signed integer), it sets up (usually) 2 bytes. So if "int x" was the first thing you declared, it would be at address 0. If you then declared "int y", it would be at address 2. If you declared char name[10], it would start at address 4 and go through address 13, and so on.

Using & and * are ways to directly reference those addresses. It's a lot easier for functions to handle pointers to data structures than the structures themselves. Thus, you would use * to declare a type as being a pointer. So you could, in fact say:

char Name[20];
char *pName = &Name;

Then you would know that Name is the 20 char string, and pName is a pointer to that string. The & references the "address" of Name for use by the pointer.

Simple, right?

mwah ha ma wah hah whah... (a la Charlie Brown, for the non-programmers)

[Twisted29]

You still need a variable. I'll try to explain, but keep in mind its been a while since I've used C.

int var = 0;

That decalres a variable and initializes it to a value. The initialization (setting it to zero) is optional, but recommended. If you dont give it a value, you cant be sure of its starting value.

int *var1 = &var;

Now I'm just making a new variable, var1. I'm setting it equal to the memory location that var is stored in. You have to think of the computer memory as chunks of information. For this example, we'll call those chunks bits (even though bit, word, and long word allocations can be used in C). Say var is stored in bit #32 on your computer. Then var1 is equal to 32. This lets you do a couple things.

cout << var1;

Prints out 32

cout << *var;

Still prints out 32

cout << var;

Prints out 0

cout << *var1;

This will print out the location of var1 in memory. Which will be someplace completely different from var (unless you can initial memory location in C? I dont know).

What I mean about the stacks and such is this.

int var[5] = 0;
int *pointer = &var[0];

I made a five digit array (list of integers) and another value that points the first address in memory of the array. Say you want to know the 3 digit. You can just add 3 to pointer and then look at what data is stored in that location. It would give you the same result as var[3];.

The whole pointer concept is probably one of the most difficult things in C++ programming (excluding OOP if you get into that). So dont worry if you dont get it. I think everything you can do with pointers, you can also do with integers. But it takes more memory and more variables. Not sucha a big problem for the kinds of code you'll be working on in school. Once you get into large scale programming or ASM stuff, then you'll need to wory about pointers. Hope this helped

/* Please excuse any errors, like I said...its been a while for me */

[CyC0Dad]

[[Wolfpack]Deqlyn Moquei]

Im not sure how close C++ is to VB6.0 but I think if int pvar is always going to be 5 then it needs to be Const con, but thats just VB6.0

[LanceMantis]

Well according to my friend in the comp sci dept. you cannot assign the value of the pointer like that. You make it point to memory address 9.
You have to de-reference it as a value. *pVar=9:
_________________
Shinu Kikai O Motomo

[Warhammer]

[Lin Sivvi Defiant Hero]

I understand what you are saying, but I'm still feel stupid I'm too young to be thinking this hard

[BitterBeerFace]

LOL, yeah, I never learned enough C++ to learn pointers, which means i know nothing about it at all

[Kilaak Kommander]

KILAAK KOMMANDER LIKE GURLS WITH BIG THINGIES.

[Twisted29]

BBF< how did you manage THAT kill? Looks like a good story....

[Lin Sivvi Defiant Hero]

Hold a medpack out and take mirror from a grenade.