Infinite Loop Help!

[Angry Food]

Hi. I don't know why why program doesn't work the way I want to.It keeps looking whenever I want to type '-1'. I know I', experiencing an infinite loop but I'm not sure how to fix it.

// exercise 3
#include <iostream>
using namespace std;
int main()
{
	double miles;
	double gallous;
	double T1miles;
	T1miles = 0;
	double Tgallous;
	Tgallous = 0;
	double T2miles;
	double MPG;
	double counter;
	counter = 0;
	while (counter >= 0)
		{
		cout << "Enter miles driven(-1 to quit): "<< endl;cin>>miles;
		cout<<"Enter gallons used: "<<endl;cin>>gallous;
		MPG = miles/gallous;
		cout << "MPG this trip: "<<MPG<<endl;
		T1miles = T1miles + miles;
		Tgallous = Tgallous + gallous;
		T2miles = T1miles/Tgallous;
		cout<<"Total MPG: "<<T2miles;
		cout<<endl;
		counter = counter + 1;}
}

[Lowest0ne]

Erase lines from your code until you isolate the issue

[Angry Food]

sorry i don't really understand what you mean, example?

[ch1215]

You haven't set the condition for the program to quit when you input -1.

[kyiro37]

When do you want it to allow "-1" to be the option to quit? Only for when they're entering the miles?

I think this will work:

if (miles==-1)
{
break;
}

If you put that after cin>>miles;, I believe it will work.

[bigdog225]

the counter shouldn't be the condition
miles is the condition
you aren't even inputting into the counter

[bigdog225]

and it doesn't test the condition again until the end of the loop

[bigdog225]

while (miles != -1 )