C++ ANYONE?

[smwilliam2]

i am suppose to right this program. Have no understanding of C++ and I am sure it would take anyone like 5 min to write up could anyone help me out? Below is what I am to do:


Ask the user to enter a radius, calculate (and output) the circumference and area of the circle.
C= 2(pi)r
A=(pi)r^2

-use variable pi and set it to 3.14159

[Wakebrad]

It's been a couple years but here goes:

#include <iostream>
using namespace std;
int main()
{
double r;
double pi = 3.14159;
cout << "Enter the radius: ";
cin >> r;
cout << "The circumference is: " << 2.0*pi*r << " the area is: " << 1.0*pi*r^2 << endl;
return 0;
}

[Wakebrad]

Oh, if that works the first time you owe me $5. You can PM me for my paypal.

Software never works the first try.

[smwilliam2]

alright I will let you know tomorrow once i get into the computer lab and try it..

i dont think i will ever make fun of a cis major again... this crap makes no sence to me

[smwilliam2]

got two errors

cin >> r; this line has an error of "unable to resolve function overload"

and

cout << "The circumference is: " << 2.0*pi*r << " the area is: " << 1.0*pi*r^2 << endl; has an error of mismath in formal parameter list

[smwilliam2]

cin >> r; this line is fine both errors are on the the other one i guess

[Wakebrad]

Sounds like your environment might not be setup right.

Try this one to see if you can at least get it to execute:

#include <iostream>
using namespace std;
int main()
{
double r;
cout<<"test";
return 0;
}

[Wakebrad]

if they're both on that one line try this then:

#include <iostream>
using namespace std;
int main()
{
double r;
double pi = 3.14159;
cout << "Enter the radius: ";
cin >> r;
cout << "The circumference is: " << 2.0*pi*r << " the area is: " << 1.0*pi*r*r << endl;
return 0;
}

[smwilliam2]

dude you are the man

[smwilliam2]

what did you change?

[b_girl]

not to sound b***hy or anything but u coulda at least attempted it yourself before asking someone else to write it for you!

anyway, add this to the top:
#include "stdafx.h"

*edit* or not... haha, it's been a couple years since i touched C++

[smwilliam2]

because I did try it myself.. this stuff means nothing to me i dont understand it one bit, the last assignment we had was to copy what he had and put it and and i got errors with no clue how to fix.

this is a intro class i took it as a gen ed aside from this the class was a joke.

[smwilliam2]

#include "stdafx.h"

what does this do?

[Wakebrad]

Ok, now that you know the problem and have the solution in front of you here's a little explanation.

#include <iostream>To write data to and from the screen you have to include this code so that the compiler recognises cin and cout
using namespace std;this defines the namespace, too complex to worry about yet
int main()This is where the code starts executing
{defines the opening of the function
double r;Declares a variable of type double. Integer is like 1,2,3,4,5. Double can have decimals: 2.4, 4.003, etc
double pi = 3.14159;define pi as a double and set it to the value
cout << "Enter the radius: ";cout<< writes to the screen
cin >> r;cin>> reads the screen into the variable r
cout << "The circumference is: " << 2.0*pi*r << " the area is: " << 1.0*pi*r*r << [/b]endl;This is the line with the problem. My mistake was that I thought r^2 would do exponent but I was wrong. What I changed it to was r*r.
return 0;This is the return value, you probably don't need to worry about this yet. Read your book or wait until your prof goes over functions/methods
}this closes the function

Your prof should have gone over some of this stuff already.

[smwilliam2]

wow i somewhat understand it actually, thank you. the prof is not a very helpful one he runs through slides in monolouge; I am sure you know a few profs like this.

Seriously, you have no idea how much you helped me out. I appreciate it

[DJew Jake]

If your taking the course are you going to expect us to write all your assignments?

[smwilliam2]

yeah can you get on my excel spreadsheets while your helping me out with this?

[Wakebrad]

I've had some profs like that, it's particularly bad in intro classes where the subject is totally new. The best way to learn is to use your book, type out the examples and run them.

No problem.

[DJew Jake]

the reason ^ did not work is because that is a bit op in c++ when you go numbe^2 its xor with 2 isnt it?

[b_girl]

smwilliam2, sorry, didn't realize you had already tried it yourself. i've been roped into "helping" (or... doing) other peoples assignments before so i get a little annoyed by it now if the person hasn't at least made an attempt first.

[DJew Jake]

incase your wonderng that means

lets sa radius - 7 thats 00000111
2 = 00000010

xor means one or the other but not both so the awsner would be

00000101 or 5

[DJew Jake]

but bit ops do not work on floating numbers thats why it didnt work.

[smwilliam2]

b_girl, yeah this is a forum where every gets on eachothers cases. but how do find yourself in doing stuff for others i mean you have a choice... maybe sub consciously you enjoy helping others lol

[b_girl]

smwilliam2, it starts out with them asking for help on how to start it... then help on how to do such-and-such, etc... and before you know it, i've done the whole thing. so now i'm a little more careful when people ask for help

some people just cut right to the chase and ask me to do the whole thing... but then they're met with a big fat no.

[DJew Jake]

I refuse to write you any code in c its so useless these days. Sorry.

[Wakebrad]

Wow, I haven't done C++ in 5 years. That's crazy. It doesn't seem like that long ago.

Interesting on the xor. Not sure I ever used that. I had a course in C and a course in C++ but work in ASP.NET and Java now.

I mooched off more people in highschool and college than I will ever be able to make up for. It feels good to give back a little

[DJew Jake]

Wakebrad, Ye well why use c++ managed languages are just as fast and you can insert assembler directly into them too so as far as im concrened c++ has very little use in todays world of on demand applications.

[Wakebrad]

Jibsta, interesting. I hadn't heard that C++ was on its way out.

I pretty much only do web apps so c++ has no use there. C# is going strong though.

[DJew Jake]

Wakebrad, Well c has obvious uses for anything low level. But 90% of user apps are now writen in managed code. Languages like C# lets big companies higher less skilled in house programmers for cheaper so its win win for everyone. Anything "hard" to write will still be done in c++.

[b_girl]

c# is the way forward for sure, i haven't done that much in it yet, but i intend to... most of my experience in the past actually lies in C and C++... doing VB at my current job though...

wanna know something sad? we still update/support VB3 apps. our boss has been very hesitant to move to VB.Net - partially cuz he's got no clue what it is. BUT, think we've managed to convince him to allow us to start moving portions of our apps across to .net now.

Wakebrad, my project over the next few weeks is actually to redesign this one product of ours so it's accessible over the web (it's currently a 16-bit app so it's gonna take some work), so that means asp.net... i might come to you with questions

[Wakebrad]

b_girl, haha no problem. I'm actually just making the switch to 2.0 so I'm still learning the new stuff but once you get the concept you should be fine. also www.asp.net has pretty helpful forums that I use when I'm stumped.

[b_girl]

Wakebrad, thanks - i'll keep that link in mind, except we don't have use of the internet at work