Problem with Do Loop

[azns123]

I'm writing a program that outputs a value based on a value the user inputs. For example, if the user inputs a value from 0 to 0.35, the program triples the value and returns it. And if the user inputs a value from 0.36 to 0.50, the program doubles it, and so on until the user enters a value less than zero, which ends the program.

  // name : Sean Hwang
// date : 5/19/2015
/*
this program will display
using variables concept
*/
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;


void main()
{
	// define variables here
	double couponvalue = 0.0;
	double couponrealvalue = 0.0;



	do
	{
                // user inputs the coupon value here
		cout << "value of coupon is: " << endl;
		cin >> couponvalue;

                // does not compute correctly
		if (0 < couponvalue < 0.36){
			couponrealvalue = couponvalue * 3;
			cout << couponrealvalue;
		}

                // does not compute correctly
		if (0.36 <= couponvalue < 0.51){
			couponrealvalue = couponvalue * 2;
			cout << couponrealvalue;
		}

                // does not return anything at all
		if (0.51 <= couponvalue < 1.00){
			couponrealvalue = 1.00;
			cout << couponrealvalue;
		}

		if (couponvalue >= 1.00){
			couponrealvalue = couponvalue;
			cout << couponrealvalue;
		}

	} while (couponvalue > 0);

	// output
	cout << "The total value of the coupons is " << couponvalue << " dollars" << endl;
}

The problem I am having is that when I try to enter any value, it returns an incorrect value or no value at all.

[mpacker]

Each comparison needs be be written out,

if (0 < couponvalue < 0.36)

Doesn't do what you think it does.

You need something like:

if (couponvalue > 0 && couponvalue < 0.36)

You've got some other things to iron out too, like the loop checking if coupon value is greater than zero after it's already processed it.

Good luck.

[azns123]

Thank you so much, the program checks properly now.