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[MagmaMcFry]

Why would you need to return those values? Just make the function return void.

[MrWillsauce]

I guess I just didn't understand class scope.

[MrWillsauce]

So should I use the structs I wrote earlier so that the values assigned to the map actually mean something? I need to manipulate those values with inputs from another file before printing them.

[MagmaMcFry]

No, those structs are completely useless and unnecessary now. To access your data, you now simply write data["sCoal"] instead of empireStocks.coal. All we did is make your data structure more simple, more flexible and less maintenance-heavy.

[MrWillsauce]

But if I write something that requires coal and no coal string was fed to the map, wouldn't things break?

[MagmaMcFry]

If you look up a key that doesn't appear in the map, the map just makes a new value for that key, and gives that one back to you, although if that's too unsafe for you (because the new value is uninitialized), you can use this:

Code: [Select]

int& getData(const string&& s) {
if (data.find(s) == data.end()) data[s] = 0;
return data[s];
}
Then just write getData("coal") instead of data["coal"].
Alternatively you could write a custom allocator for the map that allows you to continue using data["coal"] without worrying about uninitialized values, but I kinda have no idea how custom allocators work.

[MrWillsauce]

I guess leaving them uninitialized isn't a big deal. Would using a list of if statements be the most efficient way to do things for analyzing strings from the input file as commands?

[MagmaMcFry]

Leaving them uninitialized is totally a big deal, because if you access uninitialized data, you could suddenly have 1427583924 coal mines. Also, what sort of commands? Because a list of if statements is never a good idea if you want your code to last.

[MrWillsauce]

Well if I got an impossible number of coal mines, I would know that somebody's input was invalid. And commands such as "build 6 farms" or "smelt 12 iron bars". A list of commands should be fine, since the possible commands won't change at all throughout the game (although I agree a more flexible method would be much better).

[MagmaMcFry]

Wait, you're going for text-based commands? Sounds kinda evil. But yeah, command based user input is insanely painful to handle in C++; either you need a lot of framework code or you need a lot of if statements. If you want no framework at all, you could test case-by-case for equality against strings like "make iron" or "build farm". If you want more framework, you can keep a map<string, Command> of commands that have an execute(vector<string>) method, tagged by their name, and the build/make command could keep a map<string, Recipe> of recipes that are executed when its name is called. If you're really silly about it, you can make the data modifiable only through transactions with a custom Transaction class. There are tons of ways to add structure, extendability, modularity and stability.

[MrWillsauce]

Writing that kind of structure sounds far beyond my skill level. I guess it's a very long list of if statements then.

[Rose]

What you want is something like this: http://stackoverflow.com/a/237280
to split up all the parts of the user command, then just run through it piece by piece.
The next answer down also is useful.

[MrWillsauce]

I get what's being accomplished, but I don't really understand a lot of what exactly is going on in either of those.

[Skyrunner]

Go to a C++ reference site and read up on what each function does, its arguments, and the result. Should help.

[Siquo]

I finally finished code for a problem I was given in my AP CompSci class just now.  The purpose is to "Write a function that takes and integer argument.  Return true if the number is divisible by all of its digits (if a digit is 0 return false) else retuen false" Can you guys tell me how badly I messed this up-

Spoiler (click to show/hide)

public static boolean divstuff(int num)
    {
       int newnum=num; //sets initial value because otherwise I get errors
       int length = String.valueOf(num).length(); //Gets length of num
       boolean tf=false; //use this for determining if class returns true/false because otherwise errors      
       for(int count=0; count<=length; count++)
       {
          if (count==length) //if count is equivelent to the length of the number then everything is divisible
          {
             tf=true;
             break;
          }
          else  //still numbers that need to be divided
          {
             
             int temp=newnum%10;  //get's last number
             if (temp==0)  //Because I don't want divided by zero
             break; //A number can't be divided by it's factors if it has zero
             else
             if ((num%temp)!=0) //Divides num by one of it's numbers, and checks if modulo is zero
             break;
             else
             newnum=newnum/10; //get's new last number
          }
       }
       if (tf==true)
       return true;
       else return false;
   }

Also are there are any ways to improve the efficiency of this?  And are there any ways to input a number to break this?

Efficiency: As soon as you reach a digit 0, or if the number is not divisible, you can return false instead of break.
Instead of doing a count by length, you can do a while(newnum > 0){}, or even better, a custom for
You'd get:

Spoiler (click to show/hide)

Code: [Select]

public static boolean divstuff(int num)
    {
    if(!num) return false;  // return false if we get a 0
    for(int newnum = num; newnum > 0; newnum /= 10)
    {
    int temp = newnum % 10;  //gets last number
    if (temp == 0 || (num % temp) != 0)  return false; //Because I don't want divided by zero, then Divides num by one of it's numbers, and checks if modulo is zero
    newnum = newnum / 10; //gets new last number
    }
    return true;
}

But then in your own words, of course