While Loop problem?

[devindinap]

Basically, if I run the program below, the output line is blank..I honestly have no idea what to do, and I need this done. I don't want anyone to do it with me (unless i'm desperate), I just need some pointers, samples, examples, etc.




#include<iostream>
#include <string>
#include <iomanip>

using namespace std ;

int main()

{
char vehicle;
int minutein,
minuteout,
hourin,
hourout;

int hours;
double cost;

cout << "Type of vehicle: C for car, T for truck, B for bus: " << endl;
cin >> vehicle;
cout << "hours in: ";
cin >> hourin;
cout << "minutes in: ";
cin >> minutein;
cout << "hours out: ";
cin >> hourout;
cout << "min out: ";
cin >> minuteout;



hours = hourout - hourin;


while(vehicle == 'C' || vehicle == 'c') {
if(hours <= 3) {
cost = 0;
}
else {

cost = hours * 1.5;
}
}

while(vehicle == 'T' || vehicle == 't') {
if(hours <= 2) {
cost = 2.5; }

else {

cost = (hours * 5) + 2.5;
}
}

while(vehicle == 'B' || vehicle == 'b') {
if(hours <= 1) {
cost = 5.00; }

else {
cost = (hours * 7.5) + 5;
}
}

cout << cost;






system ("pause");
return 0;
}

[jim80y]

Hi,

Try stepping through your code in your head, following each executable statement from one to the next.

What do you find happens in the while loops?

Cheers,
JimbO

[Srija]

hi devindinap.......


First of all let us know what u want to do with the program..........and better to use if statement than while loop as for as my understanding.......

[Gaminic]

The output line is blank because your program is stuck in an infinite loop.

You're not supposed to use a while loop for a single execution. Now, the value of "vehicle" will NEVER change, so once it enters a loop, it will never exit. Replace with if statements (or a switch).

[mrkhn]

...
//if vehicle == C it will go inside... but when does the loop finish? 
//(When is vehicle different from 'C' or 'c' ? 
//as the value never changes... it will stay inside the loop forever
while(vehicle == 'C' || vehicle == 'c') {
if(hours <= 3) {
cost = 0;
}
else {

cost = hours * 1.5;
} 
}
...

[/b]

First why are u using a 3 while loops?
As gaminic said you should use a switch or some ifs...

The point is...

Consider that Vehicle value = 'C'
As it never changes inside the while loop it wont go out of the while so it would be an infinite loop.

[mrkhn]

If you really need to use a while loop for the program...

You should do something like...

Loop

  Switch || bunch of ifs else

  Modify type vehicle

exit when vehicle type != than the conditions of the ifs

For example