Processing 1.0 - Processing Discourse - use of objects returned from a method

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Index › Programming Questions & Help › Syntax Questions › use of objects returned from a method

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use of objects returned from a method (Read 217 times)

starkes

use of objects returned from a method
Jan 29^th, 2009, 6:41pm

Hey,

I wasn't sure how to word this question or my google searching probably would have given me better results.

I've noticed that in processing, if i have a method that returns an object, I can't use that object right as it's returned, I have to save a copy of it and then check that copy.

I thought i recalled being able to do something like the following in java:

class one
{
someObject theObject;
someObject returnObject()
{
return theObject;
}
}
one One = new one();

say class someObject contains a variable called x, I can't seem to do the following:

if((One.returnObject()).x>5)
{
// do something
}

I would have to do this:
someObject SomeObjectCopy = One.returnObject();
if(SomeObjectCopy.x>5)
{
// do something
}

is this a limitation of java 1.4 syntax? or am i nuts?

thanks.

PhiLho

Re: use of objects returned from a method
Reply #1 - Jan 29^th, 2009, 6:52pm

You are nuts! Wink

Well, no, not really.
Sometime, I prefer to use the intermediary variable. But it is rarely, if ever, needed.

Let's demonstrate that re-using your example, only using a more conventional notation (we are used to see class names with initial cap and object instances with initial lowercase letter).

Code:

class Foo
{
  Bar bar;
  Foo()
  {
    bar = new Bar(5);
  }
  Bar getBar()
  {
    return bar;
  }
}

class Bar
{
  int x;
  Bar(int i) { x = i; }
}

void setup()
{
  Foo foo = new Foo();
  println(foo.getBar().x);
}

At worse, in some case (Collections pre-Java 1.5), you need to cast the returned object to a given type before using it:

Bar b = (Bar) arrayList.get(7);
b.doSmt();

but you can even do (at the expense of some readability):

((Bar) arrayList.get(7)).doSmt();

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