C++ Tutorials - Absolute n00b spoonfeed

Consider it done

http://cpptutorials.freeforums.org/c-c-standard-library-functions-t84.html

Thanks

I looked up quite a lot about using square roots, but none were so specific on the syntax (Thank you! that finally allows me to finish my quadratic part of the ultra calculator!) so apparently to use it, you have to declare a new variable as the root of it?

So you couldn't just do

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#include <cmath>

int main ()
{

cout << sqrt (25) << "the square root of 25 is 5";
}

?




but instead

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#include <cmath>
#include <iostream>
using namespace std;

int main ()
{
float question = 25;
float answer = sqrt ( question)


cout << answer << "the square root of 25 is 5";
}

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#include <cmath>
double sqrt( double num );


That would be the actual syntax of the code.

The sqrt function returns the square root of a number. If the number returned is negative it gives you a domain error.

Doctor Salt wrote:So you couldn't just do

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#include <cmath>

int main ()
{

cout << sqrt (25) << "the square root of 25 is 5";
}

?

No, that's absolutely fine. Where you have a function that accepts a value you can use a function that returns a value as a parameter. Basically, each parameter to a function is expected to be a valid expression that evaluates to the same type as the parameter. Provided the function returns a value of the same type (or one that can be implicitly cast to the correct type - but that a whole other tutorial video for antiRTFM ) then its result can be used as the input to a function. For example,

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#define _USE_MATH_DEFINES
#include <math.h>
#include <iostream>

using namespace std;

float DegreesToRadians( const float fAngleInDegrees )
{
    return (fAngleInDegrees * (float)M_PI) / 180.0f;
}

int main()
{
    for ( float fAngle = 0.0f; fAngle < 360; fAngle += 1.0f )
    {
        cout << "Sin(" << fAngle << ") = " << sinf(DegreesToRadians(fAngle)) << endl;
    }
    return 0;
}


Rock on, hehe I learned all of this actually. In my technical training the military put me through, some craziness we have to work with ocassionally. (Work on F-16's, hehe.) Now knowing that this stuff ties into programming, when I get to the point to where I can actually make some magic happen, I'll gladly put this to use. Thanks alot!

AWESOME!

I totally got that (for the most part)

So yea I think I understand it but I still have a couple of questions:

A byte is 8 bits, which has 255 combinations (just under 256, which would start on a 9th bit I assume since that's what it does in binary). Well a kilobyte is suppose to be 1000 right? But it's not it's 1024 or something close to that...and same thing with megabytes and gigabytes. My question is if bytes are just sets of bits, then how come you can't just have 1000 sets of 8 bits, or 8000 bits?

I have recently been exposed to a '>' operator in C++, I didn't quite understand it since it was a small little internet tutorial but it was something about what they called 'nodes' and passing on pointers until you get to a 'stop' pointer or something...I can't really remember. Anyways, is the '>' operator related to the '>>' operator?

What subject would this type of stuff go into? Software engineering or hardware engineering?

I've had these questions for a while actually...

This should do the trick...

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#include <iostream>

using namespace std;


int main()
{
   int number;

   cout << "Insert a number: ";
   cin >> number;

   (number % 2 == 0) ? cout << endl << "The number is Even !\n\n" : cout << endl << "The number is Odd !\n\n";

   system("pause");
}

My version. Can someone help me with the !cin.good() I get a infinite loop.

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#include <iostream>
using namespace std;

int main(void)
{
   //declare variable
   int input;

   //Asks user to input variable
   cout << "Please enter a whole number: ";
   cin>> input;
   
   while(!cin.good())
   {
      cout << "Please enter a valid number! ";
      cin >> input;
      return 0;
   }

   while(cin.good())
   {
      if ((input%2) == 0)
      {
         cout << "\nThis number is even!\n";
      }
      else
         cout << "\nThis number is odd!\n";
      return 0;
   }
   
   


}

Here's my program for this. It's short but does the job:

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#include <iostream>

using namespace std;

int main(){
   
   int number;
   
   cout << "Enter your number: ";
   cin >> number;
   cout << endl;
   
   if(number%2 == 0){
            
        cout << "Even" << endl;
            
        }
            
   else if(number%2 == 1){
      
       cout << "Odd" << endl;
      
       }
   
   system("pause");
   return 0;
   }