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Local Inner Classes

 
Ranch Hand
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Hi All
How can a local inner class outlive its scope?
This seems to be the reason most texts give for the final modifier requirement when a local inner class is involved.
Thanks in advance.
 
"The Hood"
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You can define a variable outside of the method, then instantiate it with an object in a method. The method ends, the object is still referenced.
You could return the object at the end of the method, so that something still references it. etc.
 
Zahid, Butt
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Hi
Thanks for your answer.
Nut it is still not 100% clear, can you write some code to
illustrate this Please.
Thanks in advance.
 
Greenhorn
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I may not be very correct at syntax, but the following pseudo example may help you.
Suppose you have an interface named IShape and your local class, Rectangle, implements this interface. Now your method can create an object of type Rectangle and return it as IShape object.
See this:
interface IShape {
public void draw();
}

class Test {
public IShape create () {
class Rectangle implements IShape {
public void draw () {
System.out.println ("I am draw of rectangle.");
}
}
return new Rectangle();
}
}
public class Main {
public static void main (String args[]) {
IShape i = new Test().create();
i.draw();
}
}
Hope this helps...
Shah.
 
Zahid, Butt
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Hi
Thanks for your answer Muhammad.
How come the Compilor does not flag an error ??
Why is this possible ???
Is it because its an object, if so when do objects die in a program if you dont EXPLICITLY command it to ??
Thanks in advance.
 
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Hi Butt.
I think (I am still learning this stuff)
If you assign null to the object, it is eligible for garbage collection.
You never know, when the garbage collector will run.
The memory of the object is set free, when the garbage collector runs.
hope this is correct
Axel
 
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.
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