Trying to build a Taxi Fare Code

[dmunoz]

I'm trying to build this taxi fare calculator. I can't get the statements correct, keep getting $3.00 regardless of what options I select.

#include <stdio.h>

int main()
{
float distanceRate;
float distanceMiles;
int passengers;
int mileRate;
int firstpassengerCost;
int addpassengerCost;
int passengerCost;
int airportFee;
int distanceCost;
int totalFare;
char yes;
char no;
char airport;

printf("Are you coming from or to the airport - 1 for yes, 0 for no \n");
scanf("%i", &airport); /*User enters 0 or no*/

if (airport=1)
airportFee = 2.00;

else
airportFee = 0.00;

printf ("Enter distance to destination: \n");
scanf(" %i", &distanceMiles);

if (distanceMiles <= 1)
distanceRate = 3.50;

else if (distanceMiles >1)
distanceMiles * distanceRate;

printf("Enter the number of passengers: \n");
scanf(" %i", &passengers);

if (passengers <= 1)
passengerCost = 0.00;

else if (passengers =2)
passengerCost = 1.00;

else if (passengers >2)
passengerCost = (passengers -1) * addpassengerCost + firstpassengerCost;

totalFare = (distanceMiles*distanceRate) + passengerCost + airportFee;
// mileRate = 1.80;
// airportFee = 2.00;
// passengerCost = 0.50
printf("The total fare cost will be $%.2f\n", (distanceMiles*distanceRate) + passengerCost + airportFee);/*Calculates distance cost plus a 1st passenger rate of #1.00*/

return 0;
}

[TheToaster]

Are you making a program in C or C++? If it is the latter, I suggest you use C++ style constructs like iostreams rather than C constructs.

It would help if you reposted your code with code tags
http://www.cplusplus.com/articles/jEywvCM9/

[thmm]

else if (passengers =2)
if (airport=1) 

The comparison operator is ==

scanf(" %i", &distanceMiles);
distanceMiles is a float but you read only an int

if (airport = 1)
    airportFee = 2.00;

  else
    airportFee = 0.00;

Why do you want to store a double in an int ?

else if (distanceMiles > 1)
    distanceMiles * distanceRate;

Should you store the value of distanceMiles * distanceRate and use it?

All the mistakes cour compiler could show you if you enable warnings.

[Handy Andy]

Hello dmunoz,

PLEASE ALWAYS USE CODE TAGS (the <> formatting button), to the right of this box, when posting code.

Along with the proper indenting it makes it easier to read your code and also easier to respond to your post.

http://www.cplusplus.com/articles/jEywvCM9/
http://www.cplusplus.com/articles/z13hAqkS/

Hint: You can edit your post, highlight your code and press the <> formatting button, but you may still to indent your code.

You can use the preview button at the bottom to see how it looks.

I found the second link to be the most help.

You should compile your code and try to fix the errors and warnings before you post it. I get this when I compiled it wit VS2017 with the C++14 standards.

Severity	Code	Description	Project	File	Line	Suppression State
Warning	C4101	'yes': unreferenced local variable	f:\vs 2017\original code.cpp	15	
Error	C4996	'scanf': This function or variable may be unsafe. Consider using scanf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.	original code.cpp	20	
Error	C4996	'scanf': This function or variable may be unsafe. Consider using scanf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.	original code.cpp	29	
Error	C4996	'scanf': This function or variable may be unsafe. Consider using scanf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.	original code.cpp	38	
Warning	C4477	'scanf' : format string '%i' requires an argument of type 'int *', but variadic argument 1 has type 'float *'	original code.cpp	29	
Warning	C4477	'scanf' : format string '%i' requires an argument of type 'int *', but variadic argument 1 has type 'char *'	original code.cpp	20	
Warning	C4101	'no': unreferenced local variable	original code.cpp	16	
Warning	C4101	'mileRate': unreferenced local variable	original code.cpp	8	
Warning	C4101	'distanceCost': unreferenced local variable	original code.cpp	13	
Warning	C4244	'=': conversion from 'float' to 'int', possible loss of data	original code.cpp	49	
Warning	C4244	'=': conversion from 'double' to 'int', possible loss of data	original code.cpp	23	
Warning	C4244	'=': conversion from 'double' to 'int', possible loss of data	original code.cpp	26	
Warning	C4244	'=': conversion from 'double' to 'int', possible loss of data	original code.cpp	41	
Warning	C4244	'=': conversion from 'double' to 'int', possible loss of data	original code.cpp	44	
Warning	C4552	'*': result of expression not used	original code.cpp	35	

That is just what I get.

Looking at your code:

int main()
{
	float distanceRate;
	float distanceMiles;
	int passengers;
	int mileRate;
	int firstpassengerCost;
	int addpassengerCost;
	int passengerCost;
	int airportFee;
	int distanceCost;
	int totalFare;
	char yes;
	char no;
	char airport;

	printf("Are you coming from or to the airport - 1 for yes, 0 for no \n");
	scanf("%i", &airport); /*User enters 0 or no*/

	if (airport = 1)
		airportFee = 2.00;

	else
		airportFee = 0.00;

	printf("Enter distance to destination: \n");
	scanf(" %i", &distanceMiles);

	if (distanceMiles <= 1)
		distanceRate = 3.50;

	else if (distanceMiles > 1)
		distanceMiles * distanceRate;

Looking at the variables some are "float"s and some are "int"s. When storing a "float" in an "int" it will work, but you will loose the decimal portion of the "float" and only store the whole number.

You should initialize your variables when defined. A couple of those variables generate an error when used before they receive a usable value.

Line 20: if (airport = 1) has more than one problem. First the "=" sets "airport" to 1 which makes the condition always true even if you did not want this. so you will always be adding "2" even if you do not want to. What you need here is "==" which means to compare. Second "airport" is defined as a "char", so setting a "char" equal to an "int" will not give you what you may be thinking.

Then there is the prompt. If you are looking for a "Y" (Yes) or "N" (No) answer then say so. Also in the "scanf" you want to use "c" not "i". Removing the "\n" from the end of the string will put the input on the same line.

This should work better for you:

printf("Are you coming from or to the airport - (Y / N): ");
scanf("%c", &airport);  //User enters 'Y' or 'N'.

if (airport == 'y' || airport == 'n')  // <--- Changes case of letter.
	airport -= 32;

if (airport == 'Y')
	airportFee = 2.00;
else
	airportFee = 0.00;

There may be a better way to do the if statement at line 4, but I have not worked with C for awhile and this is the first thing that came to mind. C++ has the function "std::toupper()" and "std::olower()" for this. Not sure about C.

In line 7 this is how to compare 2 characters.

For the next part:

printf("Enter distance to destination: ");
scanf(" %i", &distanceMiles);

if (distanceMiles <= 1)
	distanceRate = 3.50;

else if (distanceMiles > 1)
	distanceMiles * distanceRate;

In line 2. The specifier should be an "f", for a floating point number, not the "i", which is an "int". With this mismatch you are most likely getting a very large negative number. Not what you want, but may work and not be noticeable.

In line 8. What is the value of "distanceRate"? Actually it makes no difference because the line does nothing. I am not sure, but I think you would want something more like this:

if (distanceMiles <= 1)
	distanceRate = 3.50;
else if (distanceMiles > 1)
	distanceRate = 3.00;

	something = distanceMiles * distanceRate;

Without the original instructions I can not say if you are even going in the right direction.

It would help if you would post thee complete instruction for this program.

For now that is as much as I have worked on. I will look the rest and see what I can find.

Andy