C++

Forum

 
 
Need help comparing char in while statment

joe864864 (249)
Hello, I am having trouble with the begging of my code it was working previously but will no longer and I have not been able to backtrack and find the problem. What was originally happening when I ran it was that it would ask for what plan but then no matter what I entered it would reply with entry not valid. Now when I try it (couple hours later(worked on some of the code further into project and had a class)) it asks for plan and when I enter a character and hit return it moves down a line and does nothing.

I am using visual studio.

Any help would be very appreciated.

For reference here is the problem I'm trying to solve.

1.Mobile Service Provider

A mobile phone service provider has three different subscription packages for its customers:

Package A: For $39.99 per month 450 minutes are provided. Additional minutes are $0.45 per minute.

Package B: For $59.99 per month 900 minutes are provided. Additional minutes are $0.40 per minute.

Package C: For $69.99 per month unlimited minutes provided.

Write a program that calculates a customer’s monthly bill. It should ask which package the customer has purchased and how many minutes were used. It should then display the total amount due. Input Validation: Be sure the user only selects package A, B, or C.

2.Mobile Service Provider, Part 2

Modify the Program so that it also displays how much money Package A customers would save if they purchased packages B or C, and how much money Package B customers would save if they purchased Package C. If there would be no savings, no message should be printed.

Here is my code

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
 

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

int main()
{
	//setting everything to 2 decimal places
	cout << fixed << setprecision(2);

	//declaring variables
	char plan, betterplan;
	int numMinutes;
	string Cmin = "unlimited";
	const int Amin = 450, Bmin = 900;
	const double AinitialCost = 39.99, BinitialCost = 39.99, CinitialCost = 39.99, AextraPerMin = .45, BextraPerMin = .40;
	double cost, save = 0;
	int overmin = 0;

	//ask user for their plan and have it inputed
	cout << "Please enter what plan you have (A, B, or C)." << endl;
	cin >> plan;
//This is where im currently haveing trouble--------------------------------------------------------------------------------------------
	//check that they entered a valid plan
	while (plan != 'A' || plan != 'B' || plan != 'C');
	{
		cout << "Your entry was invalid. Please enter A, B or C corrisponding to your plan." << endl;
		cin >> plan;
	}
	//ask user for number of minutes used and have them enter it
	cout << "Please enter how many minute you used." << endl;
	cin >> numMinutes;

	//check that they entered valid number of minutes
	while (numMinutes < 0)
	{
		cout << "Your entry was invalid. Please enter the number of minutes you used, it must be zero or greater." << endl;
		cin >> numMinutes;
	}

	//if they have plan A
	if (plan == 'A')
	{
		//check if they used more minutes then they had
		if (numMinutes > Amin)
		{
			overmin = numMinutes - Amin;
			cost = (overmin * AextraPerMin) + AinitialCost;
		}
		else
		{
			cost = AinitialCost;
		}

		//output result
		cout << "You chose package " << plan << ", which has a base cost of $" << AinitialCost << " and gives you " << Amin << " minutes." << endl;

		//check if they should of choosen a higher plan to save money
		if (cost >= BinitialCost && cost < CinitialCost)
		{
			betterplan = 'B';
			save = cost - BinitialCost;
		}
		else if (cost >= CinitialCost)
		{
			betterplan = 'C';
			save = cost - CinitialCost;
		}
	}
	//if they have plan B
	else if (plan == 'B')
	{
		//check if they used more minutes then they had
		if (numMinutes > Amin)
		{
			overmin = numMinutes - Bmin;
			cost = (overmin* BextraPerMin) + BinitialCost;
		}
		else
		{
			cost = BinitialCost;
		}
		
		//output result
		cout << "You chose package " << plan << ", which has a base cost of $" << BinitialCost << " and gives you " << Bmin << " minutes." << endl;

		//check if they should of choosen a higher plan to save money
		if (cost >= CinitialCost)
		{
			betterplan = 'C';
			save = cost - CinitialCost;
		}
	}
	//if they have plan C
	else if (plan == 'C')
	{
		//output result
		cout << "You chose package " << plan << ", which has a base cost of $" << CinitialCost << " and gives you " << Cmin << " minutes." << endl;
		cost = CinitialCost;
	}

	//output result cost
	cout << "The total cost will be: " << cost << endl;

	//output if they could of saved money
	if (save > 0)
	{
		cout << "By purchaseing plan " << betterplan << " you could of saved $" << save << endl;
	}



	return 0;
}
Last edited on
SamuelAdams (1535)
I stopped looking at line 26 but this should get you past that part.

The first problem was the semi colon.

while (plan != 'A') works but the rest of the line doesn't.

Formatting it properly didn't help so the next thing I tried was switching the || with &&.

while ((plan != 'A') && (plan != 'B') && (plan != 'C'))

At least that's how I solved it. Maybe it will help you in the future.
Last edited on
joe864864 (249)
Awesome! Thank you SamuelAdams, that fixed it!
SamuelAdams (1535)
Your welcome Joe. I don't know a good way to describe it but when you are using || and &&, then using != it seems to reverse what you normally think it will do.
Topic archived. No new replies allowed.