C++, Arrays in C/C++

Part 1

Hi, my name is Victor (Rotkiv) and I'm going to try to instruct you in the ways of the uber coder ninja monkeys. I'm not an experienced programmer at all, but hopefully you don't know how to use an array yet so that this tutorial will be useful to you.

Arrays are very important in any programming language. They give a program the ability to access a set of variables without the programmer having to specify every call or action himself. Imagine a parent that has 20 kids, how's she going to remember all of their names? So she names them after herself and gives them shirts with their own number on it. That way she can call individual ones by the number on their shirt. This analogy is supposed to infer the idea that these 'children' could be accessed by loops, but that just wasn't working.

Now to the how:

Declaration: Arrays are declared exactly like a variable. The only thing different is that there's a post fix on the end of the variable name.

Code:

int a_variable;

int an_array[];

But you have to specify a size. Size determines how many variables are in your array. so if you declare:

Code:

		
int array[10];

You essentially have 10 different variables, so far, each without a value.

Initialization: You probably know that you need to initialize a variable before it's used, if you didn't know that, you need to. You can give arrays values in any way you can give variables values.

Code:

int array[10] = {0,1,2,3,4,5,6,7,8,9};

Now all of your variables have a value 0 - 9. The curly braces are important.

A very important thing to know is when you declared an array of 10 variables, they were not named array[1] to array[10]; they were named array[0] to array[9].

Initializing an array like that is extremely boring and it's uses are very limited. So we use an arrays best friend, the loop, to make it more interesting.

Code:

int myarray[10];

for(int x=0; x<10; x++) {  // myarray 0-9, therefore the < 10
  myarray[x] = x * x;    // x squared
}          // end the loop

So our value of myarray[0] - myarray[9] is respectively 0,1,4,9,16,25, etc. until we get to the square root of 9; but, therein lies another problem. There's no output of the value we gave it. We could print like this:

Code:

cout << myarray[0] << myarray[1];

No, as programmers we refuse to do things like that, there must be an easier way! And I know that your not stupid and know that there is an easier way. We just used it:

Code:

int myarray[10];

for(int x=0; x<10; x++) {    
  myarray[x] = x * x;    // x squared
  cout << myarray[x] << endl;  // print x and a new line.
}         // end the loop

So I hope this tutorial has helped you understand how useful these things are.

Play around with them, get to know them a little, but most of all, wait for part 2.

Yes there's more; much, much more.

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