Thread: error

you should be using == not =.
the = is the assignment operator you need the equality operator ==

you want this:

while( (indicator == 'y' || indicator == 'Y') && count<=max )

= is an assignment operator.
== is an equality operator.

doh! If ya dont type fast enough around here.... Ah, well.

ok now i got it working but its outputting differently than i want it to and its giving me negative numbers

Code:

#include <iostream.h>	//include the header file
#include <iomanip.h>
////////////////////////////
//                              //		
// the mian function	//	
//                              //
////////////////////////////

int main()
{
	const int max =20;	//the heighest you can count to
	double gas[ max ];	//the amount of gas (cant be enterd more than MAX times)
	long miles[ max ];	//the amount of miles (cant be entered more than MAX times)
	char indicator = 'y';	//for checking yes no questions
	int count = 0;	// for various counting procedures

	while((indicator == 'y' || indicator == 'Y') && count<=max)	//get the info for the miles and gas
	{
		cout<<endl;
		cout<<"please enter the odometer count:";	//ask for the miles before driving
		cin>>miles[count];	//get the miles

		cout<<endl;
		cout<<"please enter the gas count:";	//ask for the gas before driving
		cin>>gas[count];	//get the gas befor driving
		count++;

		cout<<"do you want to enter again?:";	//ask if they want to enter the values after driving
		cin>>indicator;	//test to see what they choose
	}

	if(count<=1)	//if they chose the count will be 1 or less so if it is you 
		{			//cant test the value 
			cout<<endl;
			cout<<"sorry you need to enter at least 2!";  //tell them what they need
			return 0;	//end the program
		}

	for(int i=1; i<count; i++);	//set a for loop
		cout<<endl
			<<setw(2)<<i<<"."
			<<" gas purchesed= "<<gas[i]<<"gallons, " //tell them howmuch gas they purchased
			
			<<"resulted in, \n"
			<<(miles[i] - miles[i-1] / gas[i])	//tell them the efficiency of there car 
			<<"miles per gallon";
		cout<<endl;
		return 0;    //end the program
}

any help will be appreciated

Hmm... Not sure what you're trying to do exactly (what the heck is an odometer??) but...

1) for loops need a { and a } unless it's only the next line for the loop in which case you need nothing at all at the end of the line.

2) 'count' is not incremented in your while-loop

3) 'count' starts at 1 instead of 0 in the for-loop mentioned in point 1)

ie.

Code:

while(.....) {
   ....
   ....
   count++;    // increment count in your while-loop
}

for(....=0;...;...) {            // Start count off at 0 in your for-loop
   ....
   ....
   ....
}          // Use braces in your for-loop

Almosthere

>>> for(int i=1; i<count; i++);

That is a classic gotcha! The ";" completes the for loop, therefore you are incrementing i happily, but doing absolutely nothing else. almost_here has given you the syntax.

almost_here:

The odometer is the device, usually part of the speedo assembly, which logs how far you've gone.

almost_here:

The odometer is the device, usually part of the speedo assembly, which logs how far you've gone.

Thanks ... you learn something new every day don't you?

ok
thanx

what i was trying to do was to get it to display the car miles per gallon

the reason i had it (i) start at 1 is because it displays the number of times you bought gass and you cant buy gas 0 time and still get the gas milage


and one more thing what does this mean

8.85995e+006