C++ while loop

[akaicewolf]

Ok so Im trying to make the user enter an angle and if the angle is greater than 360 im trying to scale it back down by - 360, if its less than 0 I want it to + 360. However currently I cant even get it to subtract, It keeps giving me garbage output and when I try to pass it by refrence by adding a & in front of angle the compiler gives me an error

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

int main(void)
{
    double angle = 0;
	cout << "Please enter angle : " << endl;
	cin >> angle;
	
	while (360 < angle) {
	angle = angle - 360;
	cout << angle;
	}
	
	
	

	
		 

return 0;
}

[laserlight]

The indentation needs a little work, but other than that it looks okay (though you probably want to print the angle after the while loop. The "garbage output" might be because you are misinterpreting the correct output printed from within the loop.

[MilesAhead]

Instead of trying to fix invalid input, it's generally better to give an error message and quit. It's not sensible to do a calculation on 470 degrees that's really 110 degrees. It just causes confusion.

int angle = 0;
	cout << "Please enter an angle in the range 1 to 359 : " << endl;
	cin >> angle;
      if(angle < 1 || angle > 359)
         throw "input out of bounds" // or  cout << "input out of bounds : exiting" << endl

[Lindley]

Perhaps the fact that you're outputting multiple doubles in the loop without any spaces or newlines between them could be confusing you?

[akaicewolf]

Well here is the real issue I'm having I was just testing that out. I need to make a program that takes 1/10 of the max time all the way up till the max time. It seems to be working but the numbers just really don't add up

#include <iostream>
#include <cmath>
#include <string>
using namespace std;
const double g = 9.8;
double readdouble (string prompt);
double distance (double v, double angle, double g);
double ttime (double distance, double v, double angle);
double height (double v, double angle, double time, double g); 
int main(void)
{
    double v, angle, dis, total, time,h, i;
    cout << "Please enter the velocity " << endl;
	cin >> v;
	
	cout << "Please enter an angle between 0 - 360 degrees " << endl;
	cin >> angle;
    
	    
    dis = distance(v, angle, g);
    total = ttime(dis, v, angle);
    time = total/2;
    h = height (v,angle,time,g);
    cout << "The distance is: " << dis << endl
         << "The total time is: " << total << endl
         << "The height is: " << h << endl;

while (i >= time) {
	cout << angle << endl;
	angle = angle * .1;
	}

return 0;
}
double distance (double v, double angle, double g)
{
    return (pow(v, 2.0) / g) * sin(angle);
}   
double ttime (double distance, double v, double angle)
{
    return distance/(v*cos(angle));
}
double height (double v, double angle, double time, double g)
{
    return v * (sin(angle)) * time - (1/2) * g * pow(time,2.0);
}
double readdouble (string prompt)
{
    double rv=0.0;
    cout << prompt;
    cin >> rv;
    while (cin.fail() != 0)
    {
        cin.clear();
        cin.ignore(INT_MAX, '\n');
        cout << "Error" << endl;
        cout << prompt;
        cin >> rv;
        return rv;
        }
    }