Thread: Tell me about C/C++

You should also loop into while loops and for loops.

Code:

int a = 50;
do{
   std::cout << "I'm inside the loop " << a++ << std::endl;
} while (a < 10);

Code:

int a = 50;
while (a < 10){
   std::cout << "I'm inside the loop " << a++ << std::endl;
}

Have one but very important difference, see if you can figure out what it is

Well, one of them is a while loop, and one is a do while loop. I don't really understand the difference, even after reading about it.

I should look at this page on loops for ages. I have trouble taking in/reading that much information at once, mainly because of a short attention span. I'll just have to try...

Thanks, slash.
How do I run it in a window instead of terminal?

Yea... I was wondering the same thing.

I want to learn how to make a GUI. It isn't necessary at this stage though, anyway.

alright, I wrote a program that gives you the circumference of a circle after you put in the circumference and the approximate of pi.
How can I make it simpler, i.e; tell it that the variable p is 3.14, without you having to put it in.

Code:

#include <iostream>
using namespace std;

int main()
{
     int r, p, Total;

     cout << "Enter radius and pi approximate here... "

     ;cin >> r >> p;

     Total= r * r * p;

     cout << "Circumference is " <<Total << endl;

     return 0;
}

and how do I run it in a window, not terminal

Originally Posted by guitarboy

alright, I wrote a program that gives you the circumference of a circle after you put in the circumference and the approximate of pi.
How can I make it simpler, i.e; tell it that the variable p is 3.14, without you having to put it in.

and how do I run it in a window, not terminal

Code:

#include <iostream>
using namespace std;

#define PI 3.141592654357

int main()
{
     float r, Total;

     cout << "Enter radius here... "

     cin >> r;

     Total= r * 2 * PI;

     cout << "Circumference is " <<Total << endl;

     return 0;
}

First off, ints are just integers, you need decimals for this, so we use float instead. Also, your formula was wrong Circumfrance = pi time diameter, you were calculating area. lol.

#define is what's called a macro, it's not real code. When the compiler compiles your source code, the first thing that it does, it copies and pastes macros. So when the code gets compiled, the literal value of pi gets replaced at all occurrences of PI. It is standard practice to keep definitions in caps, although not necessary.

Originally Posted by ninja9578

Code:

#include <iostream>
using namespace std;

#define PI 3.141592654357

int main()
{
     float r, Total;

     cout << "Enter radius here... "

     cin >> r;

     Total= r * 2 * PI;

     cout << "Circumference is " <<Total << endl;

     return 0;
}

First off, ints are just integers, you need decimals for this, so we use float instead. Also, your formula was wrong Circumfrance = pi time diameter, you were calculating area. lol.

radius * radius= diameter, times pi

#define is what's called a macro, it's not real code. When the compiler compiles your source code, the first thing that it does, it copies and pastes macros. So when the code gets compiled, the literal value of pi gets replaced at all occurrences of PI. It is standard practice to keep definitions in caps, although not necessary.

Also, you don't really need a window yet, do you.

it would be nice to know how to do it.
And color it.
and change text color.
etc.

Originally Posted by guitarboy

radius * radius= diameter

plus, not times

Originally Posted by guitarboy

Also, you don't really need a window yet, do you.

it would be nice to know how to do it.
And color it.
and change text color.
etc.

I understand why you want to get into GUI stuff, but trust me, at this stage it'd just confuse you

You've got to get a proper handle (no pun intended) on the language before delving into external APIs

At present, you're doing really simple maths with C++
you've yet to grasp the more advanced concepts needed for GUI apps

We haven't even covered stuff outside main() yet
let alone classes, templates, memory allocation, STL, etc. etc.

Walk, then run
But right now, we're still bobing about in the sea, before we developed legs

Nice, guitarboy. It's funny how different I would do it from that. It's amazing the amount of possibilities for one single purpose.

Also, you don't really need a window yet, do you.

Originally Posted by ninja9578

You should also loop into while loops and for loops.

Code:

int a = 50;
do{
   std::cout << "I'm inside the loop " << a++ << std::endl;
} while (a < 10);

Code:

int a = 50;
while (a < 10){
   std::cout << "I'm inside the loop " << a++ << std::endl;
}

Have one but very important difference, see if you can figure out what it is

The difference has to do with where the check is made. In the first bit of code, the check doesn't happen until after what's inside the loop has been done, therefore, it ALWAYs gets done at least once, the second piece of code does the check beforehand, so it may never get called

Stick with terminals for now, I'll show you how to make a window a little later.