Invisible Objects in java -

the following code part of larger application:

public static void method_name(object setname, int setlength){     tryloop:         for( ; ; ){             try{                 setname = new stack(setlength);                 break tryloop;             }catch (instantiationexception e){                 system.err.println(e.getmessage());                 set_num(1);                 continue tryloop;             }         } } 

whenever try use stack object initialized within try block, cannot found unless reference within try block. why , how can avoid in future?

i suspect you're under impression this:

setname = new stack(setlength); 

will have impact on argument passed in caller. won't. java strictly pass-by-value, whether value primitive type value or reference.

in other words, if this:

object foo = null; method_name(foo, 5); 

then foo still null afterwards.

i suggest return value method instead. example:

public static stack method_name(object setname, int setlength){     while(true) {         try {             return new stack(setlength);         } catch (instantiationexception e){             system.err.println(e.getmessage());             set_num(1);         }     } } 

note return instead of breaking label, , while(true) find more readable for (; ;).