Multiplying an int? « cocos2d for iPhone

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Multiplying an int?

(16 posts) (7 voices)

Started 1 year ago by Joethemonkey101
Latest reply from Steve Oldmeadow

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Joethemonkey101
On probation
I'm really sorry about all the threads I've been starting, but I can't find answers to them. I was pointed to this page - http://forums.macrumors.com/archive/index.php/t-521900.html where I find this selection - The following sample function, on the other hand, takes two integer arguments and returns the result of a multiplication of those numbers:
int multiply (int x, int y)
{
return x * y;
}
but I'm not sure how to implement it into my app because this is using UIKit. I can use UIKit, but I'm having trouble with it.
Here's my code.
```
if (mole.moleHp <= 0) {
	int score;
	float kills;
	score = kills;
	score = multiply (score, 10);
	[moleToDelete addObject:mole];
}
```
Sorry again for this question, but please help me in finding the answer.
Posted 1 year ago #
abitofcode
Moderator
It's not UIKit, it's C. Stick it outside your @implementation and declare it in the header file outside the @interface. Why not stick with Objective c
```
-(int) multiply:(int)value by:(int)secondvalue
{
        return value * secondvalue;
}
```
Posted 1 year ago #
Verisutha
Member

So how does this apply to Cocos Graphics Engine?

On the flip side if you are seriously having issues with simple mechanics like the above I would suggest that you purchase some basic object-c, or even C primer books. You need to learn the fundamentals of programming before starting with libraries.

While libs are nice to help you do your coding, without fundamentals you won't be able to get very far. You don't want to treat cocos as a scripting language. It isn't one. It is a programming library/toolkit, assuming you already have a strong understanding of the basics.

Posted 1 year ago #
Joethemonkey101
On probation

@abitofcode thanks, I really thought it was UIKit. I'll go with your method.
@Verisutha sorry, I probably should have put it in a different section. What I'm really having trouble with at the moment is ints, and how to use them efficiently.

Posted 1 year ago #
David994A
Member

@Verisutha is correct as I have told you before as well.

But to your immediate question, you could simply put the multiply inline if you like:

Replace:
score = multiply (score, 10);

With:
score *= 10;

Then you don't have to worry about a function call or method. But really, all of this is fundamental stuff to learn before attempting to code a game.

Posted 1 year ago #
skyhawk
Member
As I told you in the last thread, you need to learn about programming before you can do anything else. Gonna walk you through your code:
```
if (mole.moleHp <= 0) {
	int score; // score = random number, usually 0
	float kills; // kills = random number, usually 0
	score = kills; // score = kill's random number, usually 0
	score = multiply (score, 10); // score = random number * 10
	[moleToDelete addObject:mole];
}
```
Ignoring the logic of the rest of your code, I am assuming here that you want score to always be a multiple of your kills by 10. (so 4 kills = 40 score)

If that's the case, you don't even ever need to store "score" into a variable since its value is implicit.

So assuming you have some kill variable somewhere (hopefully assigned to a real value), wherever you want to get the "Score" and display it or store it or whatever, you just return kills * multiplier (in this case, 10).
Posted 1 year ago #
Joethemonkey101
On probation

@skyhawk I'm fully aware that score and kills currently don't do anything. I'm just leaving that there to let me know that eventually I have to fix that.
@David994A Thanks, that helped. The only error that I don't know what's wrong is that int ten; is giving me the error 'ten' redeclared as different kind of symbol. I'm not really sure what's wrong, or what that means.

Posted 1 year ago #
cocos
Member

Well, it is probably as it says: 'ten' was already used in another declaration.
Change 'ten' to 'ten1' and recompile.
But I encourage you to do what others said already. Go through Obj-C primer first. And compile and understand examples from that primer. It will help you a lot. Cocos2d cannot be learned without basics.

Posted 1 year ago #
Joethemonkey101
On probation

@cocos I've tried that. For some strange reason, it still says the same thing even when I change it to ten1. And I'm positive I haven't used the variable ten before in that class.

Posted 1 year ago #
cocos
Member

Could you post the code?

Posted 1 year ago #

Joethemonkey101
On probation

-(int)multiply:(int)score by:(int)ten1 {
	int ten1;
	ten1 = 10;
	return score * ten1;
}

Posted 1 year ago #

cocos
Member

Just to make error go away:

-(int)multiply:(int)score by:(int)ten1 {
	ten1 = 10;
	return score * ten1;
}

Posted 1 year ago #

cocos
Member
Why not:
```
-(int) multiply:(int)value by:(int)secondvalue
{
        return value * secondvalue;
}
```
and call function 'multiply' with 'secondvalue' equal to 10.

In your implementation you are killing second parameter. If you do not need it this is cleaner:
```
-(int)multiplyByTen:(int)score{

	return score * 10;
}
```
Posted 1 year ago #
Joethemonkey101
On probation

@cocos Wow that was easy. I guess that method declaration also declares the int ten1?
Thanks for the help.

Posted 1 year ago #
cocos
Member

Yes, you were redefining the 'ten1' after all :)

Posted 1 year ago #
Steve Oldmeadow
Administrator

@joethemonkey101 - I have banned you for 1 week. You have been warned repeatedly about posting these type of questions. Maybe if you had posted it in the correct forum I would have let it slide but you even acknowledged you posted it in the wrong forum. If the question isn't anything to do with cocos2d then don't post it in the cocos2d support forum - it isn't rocket science.

Have a read over your first question that you asked 6 months ago.
http://www.cocos2d-iphone.org/forum/topic/5309

You haven't come very far in 6 months, maybe it is time to change strategy. Maybe you should listen to the advice that has been given to you many times and learn the basics first. If I was you I would seriously look at Game Salad, if you had been using that for 6 months you probably would have a couple of games completed by now.

Posted 1 year ago #

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