Will this code work?

here is the problem:

Allenton Water Department wants a program that calculates a customers monthly water bill. The clerk will enter the current and previous meter readings. The program should calculate and display the number of gallons of water used and the total charge for the water. The charge for water is $7 per 1000 gallons. However, there is a minimum charge of $16.67. ( in other words, every customer must pay at least $16.67)


does this code make sense?


//ch5 - 13.cpp : calculates and displays number of gallons & total charge for the water
//created/revised by <> on <8-18-10>

#include <iostream>
using namespace std;

int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;

//enter input items
cout <<"Enter the current readings:";
cin >> currentReadings;
cout <<"Enter the previous readings:";
cin >> previousReadings;

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;

//calculates the total charge
if (totalCharge >= 16.67)
{
totalCharge = (gallonsUsed / 1000.0) *7.0;
cout <<"totalCharge:" << totalCharge << endl;
}
else
{
totalCharge = 16.67;
cout <<"total charge:" << totalCharge << endl;
}
//end if

cout <<"gallons used:" << gallonsUsed << endl;
cout <<"total charge:" << totalCharge << endl;

return 0;
} //end of main function

you forgot { } brackets in your if but it should compile once you fixed that.

If it does what your question was I dont know I didnt read that I'm not going to do your homework the forum policy even states we dont do your homework

Edit: Oh and there's some other stuff wrong too but rather than telling you what it is I prefer to spend my time saying that there's something more wrong with your code and that I prefer to say this

thanks so far. could i get a hint as to what else would be wrong? like is it the if statement, or does if have to do with my logic when trying to solve the problem?


by the way, im not asking you or anyone to do my homework that is not the reason i started this thread.

use floats instead of ints

ade161, out of curiosity has your instructor taught how to step through and debug a program?

What do you think the value of totalCharge is when you execute this line of code?


if (totalCharge <= 16.67)

Quote:

---

Originally Posted by Arjay

ade161, out of curiosity has your instructor taught how to step through and debug a program?

---

not yet.

i am studying ahead.

Quote:

---

Originally Posted by gcdef

what do you think the value of totalcharge is when you execute this line of code?


If (totalcharge <= 16.67)

---

16.67

:D it is *\(0.0)/*

Quote:

---

Originally Posted by ade161

16.67

---

Why would you think that? And if you already know its value at that point, why use an if statement?

Quote:

---

Originally Posted by GCDEF

Why would you think that? And if you already know its value at that point, why use an if statement?

---

because they have to be charged 16.67 no matter what.

Quote:

---

Originally Posted by TheComputer

:D it is *\(0.0)/*

---

what are you indicating?

Hello, ade buddy :wave:

As the minimal totalcharge is 16.67, formula to calculate totalcharge should come first before the conditional check against the minimum value. Other than that, your program looks fine to me

Quote:

---

Originally Posted by Pocoya

Hello, ade buddy :wave:

As the minimal totalcharge is 16.67, formula to calculate totalcharge should come first before the conditional check against the minimum value. Other than that, your program looks fine to me

---

how does this look?

//ch5 - 13.cpp : calculates and displays number of gallons & total charge for the water
//created/revised by <> on <8-18-10>

#include <iostream>
using namespace std;

int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;

//enter input items
cout <<"Enter the current readings:";
cin >> currentReadings;
cout <<"Enter the previous readings:";
cin >> previousReadings;

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;

//calculates the total charge
if (totalCharge >= 16.67)
{
totalCharge = (gallonsUsed / 1000.0) *7.0;
cout <<"totalCharge:" << totalCharge << endl;
}
else
{
totalCharge = 16.67;
cout <<"total charge:" << totalCharge << endl;
}
//end if

cout <<"gallons used:" << gallonsUsed << endl;
cout <<"total charge:" << totalCharge << endl;

return 0;
} //end of main function

Code:

---

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;
totalCharge = (gallonsUsed / 1000.0f) * 7.0f;

//calculates the total charge
if (totalCharge < 16.67f)
{
totalCharge = 16.67f;
}

cout <<"total charge:" << totalCharge << endl;
//end if

---

Quote:

---

Originally Posted by ade161

how does this look?

//ch5 - 13.cpp : calculates and displays number of gallons & total charge for the water
//created/revised by <> on <8-18-10>

#include <iostream>
using namespace std;

int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;

//enter input items
cout <<"Enter the current readings:";
cin >> currentReadings;
cout <<"Enter the previous readings:";
cin >> previousReadings;

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;

//calculates the total charge
if (totalCharge >= 16.67)
{
totalCharge = (gallonsUsed / 1000) *7;
cout <<"totalCharge:" << totalCharge << endl;
}
else
{
totalCharge = 16.67;
cout <<"total charge:" << totalCharge << endl;
}
//end if

cout <<"gallons used:" << gallonsUsed << endl;
cout <<"total charge:" << totalCharge << endl;

return 0;
} //end of main function

---

There's nothing between these two statements to change the value of totalCharge

float totalCharge = 0.0;
if (totalCharge >= 16.67)

Quote:

---

Originally Posted by ProgrammerC++

Code:

---

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;
totalCharge = (gallonsUsed / 1000.0f) * 7.0f;

//calculates the total charge
if (totalCharge < 16.67f)
{
totalCharge = 16.67f;
}

cout <<"total charge:" << totalCharge << endl;
//end if

---

---

1. why would you calculate the total charge along with the gallons used in the same statement? To me it should be included in the if statement as a false path wouldnt you agree?

Oh, heavens... :cry:

;) The last few post have been very straightforward, please try to concentrate.

Imagine you're the CPU executing the code, line by line. This is a part of your original program:

Code:

---

// You're interested in totalCharge, ignore other stuff.
int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;    // OK. Now totalCharge = 0.0 [remember the value]

//enter input items
cout <<"Enter the current readings:";    // totalCharge hasn't changed [still 0.0]
cin >> currentReadings;                    // totalCharge hasn't changed [still 0.0]
cout <<"Enter the previous readings:";  // totalCharge hasn't changed [still 0.0]
cin >> previousReadings;                  // totalCharge hasn't changed [still 0.0]

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;  // totalCharge hasn't changed [still 0.0]

//calculates the total charge -- BUT totalCharge hasn't changed [still 0.0]
if (totalCharge >= 16.67)  // totalCharge hasn't changed [still 0.0], so...
{
    // will this execute?
    totalCharge = (gallonsUsed / 1000) *7;
    cout <<"totalCharge:" << totalCharge << endl;
}
// etc...

---

Quote:

---

Originally Posted by TheGreatCthulhu

Oh, heavens... :cry:

;) The last few post have been very straightforward, please try to concentrate.

Imagine you're the CPU executing the code, line by line. This is a part of your original program:

Code:

---

// You're interested in totalCharge, ignore other stuff.
int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;    // OK. Now totalCharge = 0.0 [remember the value]

//enter input items
cout <<"Enter the current readings:";    // totalCharge hasn't changed [still 0.0]
cin >> currentReadings;                    // totalCharge hasn't changed [still 0.0]
cout <<"Enter the previous readings:";  // totalCharge hasn't changed [still 0.0]
cin >> previousReadings;                  // totalCharge hasn't changed [still 0.0]

//calculates the gallons used
gallonsUsed = currentReadings - previousReadings;  // totalCharge hasn't changed [still 0.0]

//calculates the total charge -- BUT totalCharge hasn't changed [still 0.0]
if (totalCharge >= 16.67)  // totalCharge hasn't changed [still 0.0], so...
{
    // will this execute?
    totalCharge = (gallonsUsed / 1000) *7;
    cout <<"totalCharge:" << totalCharge << endl;
}
// etc...

---

---

so here is the corrected version

#include <iostream>
using namespace std;

int main()
{
//declare variables
float previousReadings = 0.0;
float currentReadings = 0.0;
float gallonsUsed = 0.0;
float totalCharge = 0.0;

//enter input items
cout <<"Enter the current readings:";
cin >> currentReadings;
cout <<"Enter the previous readings:";
cin >> previousReadings;

//calculates the gallons used and total charged
gallonsUsed = currentReadings - previousReadings;
totalCharge = (gallonsUsed / 1000) *7;

//calculates the total charge
if (totalCharge < 16.67)
{
totalCharge = 16.67;
cout <<"total charge:" << totalCharge << endl;
}
//end if

cout <<"gallons used:" << gallonsUsed << endl;
cout <<"total charge:" << totalCharge << endl;

return 0;
} //end of main function





does it make sense?

attention everyone:
i debugged the program (i used a set of sample data) and the results are as shown. Is this correct?


Enter the current readings:16000
Enter the previous readings: 13000
gallons used:3000
total charge:21
Press any key to continue...

Learn another profession

Quote:

---

Originally Posted by ProgrammerC++

Learn another profession

---

did you read my previous post above?

obviously not...

Quote:

---

Originally Posted by ade161

did you read my previous post above?

obviously not...

---

I think he is suggesting that you check your own work.

In other words, there's no need to ask a programming forum to check the math for you.

Looks like you are just starting out, and at least you're making an effort with this.

When you test something, you want to go through the main paths, and also try some boundary conditions, or input that is just on the boundary between two cases.

For this program, you want to at least try input that gives you a charge that would be less than 16.67, exactly 16.67, and more than 16.67. Ideally you would try extreme cases, e.g. what happens for negative numbers, invalid numbers, very large numbers etc.

Looking at the code you posted, I think you have at least a minor bug still to find.

Stylistically, you should keep code as simple as possible.
Why write totalCharge = (gallonsUsed / 1000) *7 when you could write totalCharge = gallonsUsed *.007?

Also, the requirement is a little vague to me. You may very well be interpreting it correctly, but $7 per 1000 gallons could also mean that the charge is always a multiple of $7. If I were given that assignment, I'd ask for clarification.