Processing 1.0 - Processing Discourse - return reference of a class in a function

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return reference of a class in a function (Read 365 times)

mcanet

return reference of a class in a function
Nov 28^th, 2008, 11:01pm

Maybe someone answer this before, but I didn't find it. I don't find how to return reference of a class in a function.

I was trying somethings with a small example to reduce complexity and find how to do it.

Code:


class image
{
  int width;
  int height;
}

image getImageSize(int x, int y)
{
  image temp = new image();
  temp.x = x;
  temp.y = y;
  return temp;
}

Error display is:
expecting SEMI, found 'getImageSize'

PhiLho

Re: return reference of a class in a function
Reply #1 - Nov 28^th, 2008, 11:54pm

The main culprit is that when you define a function, you have to define setup() as well.

Other issues:
- You have width and height fields, but set x and y...
- You shouldn't use 'image' as class name, as you can see from syntax highlighting, it is a keyword (it is the name of a function in processing).
To avoid such clash, tradition is to name classes with an initial uppercase letter. Here, I would use ImageSize, for example.

sw01

Re: return reference of a class in a function
Reply #2 - Nov 28^th, 2008, 11:57pm

Try this.
image i;

void setup(){
i = function(10, 10);
}

void draw(){
i = function(11,11);
}
image function(int x, int y){
image temp = new image();
temp.x = x;
temp.y = y;
return temp;
}

class image {
int x, y;
}

I would suggest avoiding the word image: http://processing.org/reference/image_.html

Also, you are using "global" variables "width" and "height". I'd avoid that as well, making it more specific to your need, or adhering to some idiom, like adding a trailing underscore to indicate that this is a local or class variable.

Update: oh, PhiLho got to it first.

mcanet YaBB Newbies Offline Posts: 36 uk	Re: return reference of a class in a function Reply #3 - Nov 29^th, 2008, 11:41am Thanks to both. The code "sw01" works perfectly and it is just what I was trying to do. I didn't see this sintax in any place before now and I think is sometimes usefull.

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