Global variable???

[loopy]

Hello all, i'm working on a text based rpg (does'nt everyone) and i need a variable to add to through out the function's. Just to show i only come here when i need to i've tryed :

#define B 0

but when i add to it i get wrong output. My intention is for the user to get more experience as he/she perform's "trick's".
Any help would be much appreciated.
Thank's.

[Azuth]

If this is just a simple program, don't you just need to declare your variable outside of your function?

Like

#include <fstream>

int i_experience=0;

int main (void)
{
i_experience=i_experience+25;
cout << i_experience;

return 0;
}

[loopy]

Ok now i've tryed :

#include <stdio.h>

#define OLIE 10
#define FLIP_KICK 50
#define BIG_JUMP 30
#define SWITCH 40

int b=0;

then i add to it:

int curb()
{
  int z;
  clrscr();
  printf("Were coming up to a waxed curb, what do you want to do, make it fast\n");
  printf("1. do an olie over it.\n");
  printf("2. do a flip kick onto it.\n");
  printf("3. do a big jump over it.\n");
  printf("4. do a switch onto it.\n");
  printf("5. exit\n");
  scanf("%d", &z);
  if ( z == 1 )
  b + 10;
  else if (z == 2)
  b + 50;
  else if (z == 3)
  b + 30;
  else if (z == 4)
  b + 40;
  else
  exit();
  printf("%d", b);
  printf(" point's\n");
  return z; 
}

but when i output the value of b it's zero. What's up?

[Shiro]

If you want to change the variable of b, you need to use the assignment operator =, you can use it like this:

{pre: b = 0}
b = b + 10;
{post: b = 10}

[loopy]

Great shiro, i just hope i learned something from this.

[Hammer]

>b = b + 10;
Or the shorthand way like this:

b += 10;
/* is the same as */
b = b + 10;

[Prelude]

#include <stdio.h>

#define OLIE 10
#define FLIP_KICK 50
#define BIG_JUMP 30
#define SWITCH 40

int b=0;

There's no need to assign zero to b. Since it's global that will happen by default.

-Prelude

[Unregistered]

There's no need to assign zero to b. Since it's global that will happen by default.

it certainly doesn't hurt anything...it fact i think it's a good idea. it makes the variables initials values more explicit...

[Prelude]

>it certainly doesn't hurt anything
It doesn't hurt, it doesn't help. Thus it becomes a matter of style, I was merely informing the OP of an alternative.

-Prelude

[Azuth]

Don't you think it's good habbit for new coders to get into; to initialise all variables, global or not?

I understand you're just pointing out that it doesn't have to be done, but for a beginner learning to code, should we be applying an "if it aint broke, don't fix it" rule? Also, I would probably want to know what my global variables are initialised to in a game, since I'd likely have them all in the same place, it would probably aid readability to inialise even the ones I wanted to be zero.

My logic behind this is the same as my understanding of the logic behind..

void myfunction (void)
{
....
}

as opposed to

void myfunction()
{
....
}

It shows us that the coder explicitly didn't want to pass arguments to that function, as opposed to perhaps having just forgotten.

There's probably more behind that than I know, and quite likely other reasons / purposes too. I don't claim this is right, just my point of view. I'm interested in other peoples opinions on this, even though it is really a 'style' question.

[quzah]

> Don't you think it's good habbit for new coders to get into; to
> initialise all variables, global or not?

Yes, always. The only variables that are "safe" to not bother initializing are static variables. Even then, they're initially set to zero, but subsequent uses will contain whatever they held last, so you may need/want to initialize them always before using.

Quzah.

[Shiro]

> Don't you think it's good habbit for new coders to get into; to
> initialise all variables, global or not?

In general, explicit initialisations make code more easier to read, especially if defined constants or enum constants are used. Even if automatical initialization is done. Writing readable code is very useful.

[loopy]

I understand you're just pointing out that it doesn't have to be done, but for a beginner learning to code, should we be applying an "if it aint broke, don't fix it" rule?

I posted my code to another board i'm a part of, and one said in so many word's

. Another, possibly 'cleaner' implementation might be to have the function return the point values themselves, then you could have the function calls increment the total point variables. For instance, you can move the declaration of gl_points into your start() routine, and use:

gl_points += highpark();

Then declare a local variable within each subroutine called 'pts' or something similar:

pts += rail();

See what I mean? This would be a more 'object oriented' solution, because the function calls are not modifying your global variables. You'd find that if you were to start modifying and expanding this program, that it is often easier if each module is 'self contained' without having to worry about variables that are declared outside itself. I would declare gl_c in each function seperately as well, since it's not being used globally. I know this seems tedious, but you'll find that as the code gets more elaborate, this allows you to keep track of things more easily. It's a good idea to develop good coding habits early on, so you don't become too lazy as things progress.

So i have two different opinion's, one say's don't modify global variable's to keep thing's 'clean' another say's if it ain't broke. It would be alot easier for me to modify global variable's. What's the genral consensus here.
Thank's for your time.

[loopy]

Never mind, a board search turned up some good result's, anyone interested in the do's and do not's of global variable's look here