oop - Accessing a private element through an inline created object in java -

i new java , trying accessing methods , encountered not understand. code below working fine, prints 9 , not giving compilation errors. think code should give compilation error , number should inaccessible test method, since new human() instance of totally different class. can explain me happening here ?

public class test{           public static void main(string[] args) {         int number = 9;          test("holla",new human(){                @override             void test() {                 // todo auto-generated method stub                 system.out.println(number); // think line should not compile             }                        });         }      private static void test(string ,human h){                     h.test();                }     }  

human class

public abstract class human {            abstract void test();     } 

this valid (for java8 - prior that, need thje final keyword when declaring number):

• you create anonymous inner class extends human , provides required implementation of test() method.
• that method using variable enclosing "scope" - , compiler smart enough detect variable in fact constant - there no other subsequent assignments it.

in order "invalidate" example: add assignment

number = 42;  

within main method - after defining anonymous inner class. or use version of java older java8.

keep in mind anonymous inner classes closures, , jvm copying values required "inside" outside. when outside value changes - value should copied. see here further reading.

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