First app without tutorial holding my hand...

[borkus]

Hey to all. This is my first posting showing some code that I have come up with without a tutorial, like the title says. It's pretty simple in that I'm only a week into C++.

#include <iostream>
using namespace std;

	double x = 0; // always assign an intial value to a variable to ensure they don't carry something from memory
	int y = 0;


/*---------------------------------------------------------------------------*/
double a; // call the variables within the function to avoid global variables
double tipCalculator (double a)
// multiplying an input by 15% (typical tip) and storing that data
{
	return .15 * x;
}
/*---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*/
double b;
double billTally(double b)
{
	// the bill and the tip combined
	return tipCalculator(a) + x;
}
/*---------------------------------------------------------------------------*/

/*int divideBill(int y)
{
	cin >> y;
}*/

/*---------------------------------------------------------------------------*/
double c;
double billPerPerson(double c)
{
	// taking the final total and dividing it between the people present
	return billTally(b) / y;
}
/*---------------------------------------------------------------------------*/

int main () 
{
	
	// gives the "bill" a floating point to allow decimal points
	cout << "Please enter the bill to see the tip required" << endl;
	// user input. use of new line for clarity on inputing number
	cin >> x;
	// store user input into variable for later use
	cout << "The bill is $";
	// notice no new line so that x will be displayed directly behind it
	cout << x << endl;
	cout << "The tip to the waitress is $";
	// no new line again for the same reason
	cout << tipCalculator(a) << endl;
	// use function to determine percentage of bill, in this case 15%
	cout << "And the bill including the tip will be $";
	cout << billTally(b) << endl;
	// this is the tip and the bill added together for the final tally
	cout << "And now enter the number of people in your party. ";
	cin >> y;
	cout << "Your bill is going to be $";
	cout << billPerPerson(c);
	cout << " per person." << endl;
	//cout << a << endl; for debugging purposes
	//cout << b << endl; for debugging purposes
	//cout << c << endl; for debugging purposes
	return 0;
}

Like I said, it's pretty simple. But, I was proud of it none the less. The idea came from playing on my phone one day and noticing an app that was just like this one and I took what I knew so far and applied it to that principle. It is working like I expected. The only thing that I have a question about is forcing a double to display two decimal places regardless of the output. But in all honesty I haven't had time yet to research that on my own. I was more looking for some advice on the structure of the application itself in regards to habits forming along the lines of employment. I have given it a lot of thought being into my last semester of my Associate's in Applied Sciences and Technology and think my next path will be a Bachelor's in Business Information and Technology. And with this path there will be extensible programming within the course and I would like to get a jumpstart before getting there. I saw in a thread just a little bit ago someone (I believe Disch) recommending against using using namespace std; and will take that knowledge forward. If anyone could take a quick look and just give a small review on how I am doing so far it would be much appreciated. My next project will be an Ohm's law calculator and I will post as a work in progress to get feedback as it goes. Thanks to all for reading.

[Disch]

You almost have the right idea here with the function parameters, but you're using globals, and are completely ignoring the values you pass to the functions.

You're also doing a few other weird things, like making global copies of the function params right above the function body.

//  double x = 0;
//  int y = 0;  // get rid of these lines.  You don't want global variables 

//  double a; // get rid of this, you're making a global here.  You don't want that
double tipCalculator (double a)  // 'a' is defined here, so you don't need above line
{
    //return .15 * x;  // don't use x, use the value passed to the function:  a
    return .15 * a;
}

billTally and billPerPerson have the same problem as tipcalculator.


After that, you just need to put defintion for 'x' and 'y' in main() (read: not globally). You might also want to give them more descriptive names. Then you should be good to go.


Lastly, coming from someone who worked in the service industry... 15% is a sorry tip. People should tip 20% ;P 20% + change if the service was really good. 15% is for bad service.

[Computergeek01]

In case you were wondering it's perfectly ok to call functions in line with other data passed to cout. For example lines 51 and 53 can be written like this:
cout << "The tip to the waitress is $" << tipCalculator(a) << endl;

As for you question about getting the output to display with two decimal places: http://www.cplusplus.com/reference/iostream/ios_base/precision/

[borkus]

Thanks for the responses, guys. It took me a bit to get back to this. Here is what I have so far.

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


/*---------------------------------------------------------------------------*/
double tipCalculator (double tipFromBill)
// multiplying an input by 30% (typical tip) and storing that data
{
	double bill;
	tipFromBill = .30 * bill;
	return (tipFromBill);
}
/*---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*/
double billTally(double tipAndBill)
{
	// the bill and the tip combined
	double tipFromBill, bill;
	tipAndBill = tipFromBill + bill;
	return (tipAndBill);
}
/*---------------------------------------------------------------------------*/
double billPerPerson(double billPerPerson)
{
	// taking the final total and dividing it between the people present
	double tipAndBill, howManyPeople;
	billPerPerson = tipAndBill / howManyPeople;
	return (billPerPerson);
}
/*---------------------------------------------------------------------------*/

int main () 

{

	cout << "Please enter the bill to see the tip required" << endl;
	// user input. use of new line for clarity on inputing number
	double bill = 0;
	cin >> bill;
	// store user input into variable for later use
	cout << "The bill is $";
	// notice no new line so that x will be displayed directly behind it
	cout << fixed;
    cout << setprecision (2) << bill << endl;
	cout << "The tip to the waitress is $";
	// no new line again for the same reason
	cout << fixed;
	cout << setprecision (2) << tipCalculator << endl;
	//use function to determine percentage of bill, in this case 30%
	cout << "And the bill including the tip will be $";
	cout << fixed;
	cout << setprecision (2) << billTally << endl;
	// this is the tip and the bill added together for the final tally
	cout << "And now enter the number of people in your party. ";
	unsigned int howManyPeople;
	cin >> howManyPeople;
	cout << "Your bill is going to be $";
	cout << fixed;
	cout << setprecision (2) << billPerPerson << " per person." << endl;
	return 0;
}

I tried to clean it up the best I could. I also removed the global variables. I'm still not positive if I am doing the functions correctly. The setprecision statement was working correctly until I altered the code to remove the variables. Now it's giving me a warning that the address will always return as true and is not outputting the correct values. If you enter $34 under the bill, it says the tip is $1, and the bill total is $1. I can't figure out what I'm doing wrong... Could someone please take a look again and point me further in the right direction please? And thank you very much for the help so far.