Thread: Easy beginner's question about pointers

Hello everyone, so I'm in an intro to programming in C class and have a homework assignment due. It's almost done and pretty awesome except for one function that is giving me a problem. It looks like this:

Code:

//uses MoneyMenu function to display and collect dollar amounts from the user 
//uses CheckMoney function to keep comparing the added deposited amount to the item cost.
void GetMoney(double *bank, double item_cost, char selection)
{
	MoneyMenu(&bank, item_cost);	
	CheckMoney(bank, item_cost);
}

I don't understand how CheckMoney can call on the parameter bank, when GetMoney doesn't contain the information for bank, it uses the pointer *bank. When I try to do the above, my complier sticks it's tongue out at me and goes pbbbbbbbbbt. The tricky part is that the parameters for all the functions here HAVE to stay the same. They were assigned by the professor. So is there something I'm not getting, or is this a typo on the professor's behalf. (I've already emailed asking but in true fashion, he's taking his time getting back to me). Thanks!

I'll bet your compiler gives a more detailed diagnostic than that.

It's very, very, very hard to figure out what's going wrong with your code when you show neither the prototype for the function giving you the problem nor the actual error message itself.

Also, what do you mean "call on the parameter bank"? If you mean just using "bank" instead of "*bank", there's nothing wrong with that: "bank" is a pointer, "*bank" is a double.

The prototypes are these:

Code:

//uses MoneyMenu function to display and collect dollar amounts from the user 
//uses CheckMoney function to keep comparing the added deposited amount to the item cost.
void GetMoney(double *bank, double item_cost, char selection);  

//Displays the codes for money input- gets user input amounts 
//compares the int codes and updates the bank amount entered
void MoneyMenu(double *bank, double item_cost);

//compares the amount the user has in the bank to the price of item selected. 
//It returns 1 if the amount is enough to cover the cost, 0 if there is not enough.
int CheckMoney(double bank, double item_cost);

And the errors my complier gives are these:

Code:

1>------ Build started: Project: appStore, Configuration: Debug Win32 ------
1>  appStore.c
1>c:\documents and settings\kyle\desktop\intro to programming in c\appstore\appstore.c(138): warning C4047: 'function' : 'double *' differs in levels of indirection from 'double **'
1>c:\documents and settings\kyle\desktop\intro to programming in c\appstore\appstore.c(138): warning C4024: 'MoneyMenu' : different types for formal and actual parameter 1
1>c:\documents and settings\kyle\desktop\intro to programming in c\appstore\appstore.c(139): error C2440: 'function' : cannot convert from 'double *' to 'double'
1>c:\documents and settings\kyle\desktop\intro to programming in c\appstore\appstore.c(139): warning C4024: 'CheckMoney' : different types for formal and actual parameter 1
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Thank you guys.