Giygas learns the art of C++

So uh, yeah, may seem wierd that i'm posting an "update" on a DOS calculator but
I made the answers and input questions less wordy and more to the point, also changed the layout to make it easier to see which number for which command. Aso added square root.
Other than add a few more commans, I don't think I can do much more with tis calculator and should move on to something else soon.

yeah, you clearly understand flow control, basic arithmetic operations and input/output. go to the next concept now, and make something out of it too.

my recommendation: you've apparently got random down too, so when you get to arrays, see if you can figure out how to shuffle a deck of 52 cards and deal them out.

(oh, if you haven't already, figure out how to swap variables)

also floats don't support the full integer range that ints do (precision-wise); if you convert a float to an int you could potentially lose information

doubles not only have the full range but also an extra ~20 bits worth (if your ints are represented as 32-bits anyway), but of course are twice the size

i'm pretty sure floats and doubles can be used for this is well, but yeah precision conflicts will likely bite you if you try

{Lightnings Seal of Approval}

Excellent, then- I guess my calculator is finished now ( Just added the function that clears the screen after you recieve your answer to avoid clutter ), so I guess I will be moving onto some slightly more advanced concepts.

More specificly, Control Structures and Functions.

Thanks for your support, guys- It really helps when other people know about it, or are learning to. :3.

This post has been edited by Giygas on Sep 24 2009, 07:47 PM

Looking through Structure, I realise that almost everything covered there was already present in my calculator, like if, else if, else, etc. And I am used to it.
However, Functions I have not used in my calculator, or even used extensively. Because I only have Functions to work with to expand, I am not sure what tool I can create that uses alot of functions with differen't formats.
Basiclly, a program that would show me how important functions can be in simple operations, and can get me used to using them, like the calculator did for input/output and commands.

Structures and classes are extremely similar; almost exactly the same. Essentially, they're variables that contain other variables. Structures contain only variables, while classes can also contain functions. However, you cannot make any non-variable code outside of functions. For example:

struct user
{
std::string username;
std::string password;
};

And to call each, you would just refer to user.username and user.password. However, you cannot define these variables from within a function. Classes are a little different. You have to prefix definitions of functions and variables with public: or private: depending on whether or not the function/variable will be used only by the class or by other functions

For example
class user
{
public: std::string username;
private: std::string password;

public: bool confirm_login()
{
if (username=="User" && password=="Password")
{
return true;
}
else
{
return false;
}
}
};[/code]

Essentially, calling "user.username" is allowed, but "user.password" will return an error. You can call user.confirm_login() to check the login. It's simple once you get used to it, and object-oriented (structures and classes) programming is extremely useful in many cases.

There is no difference between a struct and a class in C++, except that all members and inheritance defaults to private for a class, and public for a struct. Go ahead and define all the member functions you want in a struct, not that you generally have a reason to.

Oh! I think I get it now- I thought classes ere just a fancy way of introducing functions- but I think I get it now :3
Using classes and functions, i'll probrably see if I can, again, make a simple calculator. I think that's the best way of getting used to using them.

Arrays are very strange to work with!
As annoying as it is to have to define each number in an array, they seem to be very useful is many situations.

Like Lightning suggested, I am going to use Arrays to shuffle and deal 5 cards from a deck.
How I will make sure no two cards are repeated... I do not know, but I guess that's what I am doing this for :D

you don't always have to do this

the card sequences in particular can be generated through a loop, all you really have to do is tell C++ how large the array needs to be (this depends on if you're using a single array for every card, four separate arrays, or whatever

Oh?
So using a loop, I could do,

card[4][52];

Without having to name each variable?

int deck[52];

should suffice.

then fill it up with unique values
and then shuffle it.

that's how to avoid duplicates

thinking about how to "shuffle" is an exercise that should get you thinking a little like a programmer

This post has been edited by Lightning on Sep 25 2009, 12:20 PM

Oh alright, thank yo Lightning.

I guess I have to think for myself here, which isn't really a bad thing.
As long as I get the cards shuffled without duplicates, i'll be happy!

do you know how to swap variables?

I understand what it means, but I not how to use it, really.
Would that make life alot easier?

edit: It makes use of pointers, right? I want to make sure I have the basic idea of them before using them!

This post has been edited by Giygas on Sep 25 2009, 12:25 PM

no pointers yet.

int a = 5; int b = 8;

swap their values so that a ends up with 8 and b ends up with 5. that's a prerequisite for "shuffling"

This post has been edited by Lightning on Sep 25 2009, 12:55 PM

Hmm...
Looks like i'm going to be doing some trial and error

But first,



This will be the base part for when I get the shuffle working.
Whee~

Can I have my cookie now :D?

This post has been edited by Giygas on Sep 25 2009, 01:24 PM

...or you could just use the standard library one, I guess. the point was for you to write it yourself =P

GOD FFFFFFFFFFF

Back to square one then :C
But I think I can do it now that I understand the basic idea, so maybe it won't be as bad as I think :3

This post has been edited by Giygas on Sep 25 2009, 01:33 PM