Thread: Choosing a variable based on user text input.

I have an assignment to write a simple interpreter for a made-up programming language, the code for which will be passed in a text file; for example,

INC(A)

would perform:

A++;

(the variable A is predefined). I know how to do most of it, but one part has stumped me: how do I tell C++ that it has to incriment the variable A? I could do it using an if or a case statement like:

Code:

void increment(char varName) {
    if(varName ==  'A') {
        A++;
    }
    if(varName ==  'B') {
        B++;
    }
}

but that gets ugly fast, considering there are five "functions" and ten variables. Any alternative ideas? I'm not looking for someone to do the work for me, but a hint on how to get C++ to pass the correct variable based on text input would be awesome. Thanks in advance.

Not quite. Here's what I mean.

let's say A and B are global variables and accessible from anywhere in the program.

Code:

int main() {
    char buffer = new char;
    A = 0;
    B = 0;
    cin >> buffer;
    increment(?);
}

Now, based on whether A or B was entered into buffer, I have to pass the variable A or the variable B to the incriment method. Is there any way to do it other than an if statement?

Thanks a lot. I modified it, and it seems to work:

Code:

#include <iostream>
#include <string>
#include <map>

using namespace std;

int main()
{
	string info = "A";
		
	map<string, int> myAssocArray;

	myAssocArray["A"] = 10;
	myAssocArray["number"] = 30;
	myAssocArray["strawberry"] = 2;

	myAssocArray["A"]++;

	cout<<myAssocArray["A"]<<endl;

	cout<<myAssocArray[info]<<endl;

	return 0;	
}

The one problem is that it throws a ton of warnings (not errors, though) when compiled in Visual C++ 6.0 (I attatched a text file with them). Is there any way to disable warning display? It's making it hard to find the errors.

Hi,

I was going to say something about that but I forgot. If I remember correctly, those warnings are caused because VC++6 can't handle long variable names and the STL uses variable names that are too long. Someone once directed me to some add on that stiffles the warnings, but it doesn't work completely.

See here for a fix(look under the heading Standard Template Library):

http://www.msoe.edu/eecs/cese/resour...vcmfc/msvc.htm

msoe id go there, but its 8 grand a quarter