Shadowing in Java

[Tiam Bezalel]

Hi,
I am preparing for the 1Z0-808 exam and I would like to understand shadowing in java. Please help me to understand why this code produces "99" at the end.

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package shadowing;

/**
 *
 * @author xxxxxx
 */
public class Bar {

    int barNum = 28;
   
}

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package shadowing;

/**
 *
 * @author xxxxx
 */
public class Foo {

    Bar myBar = new Bar();

    void changeIt(Bar myBar) {
        myBar.barNum = 99;
        System.out.println("myBar.barNum in changeIt is " + myBar.barNum);
        myBar = new Bar();
        myBar.barNum = 420;
        System.out.println("myBar.barNum in changeIt is now " + myBar.barNum);
    }

    public static void main(String... arg) {
        Foo f = new Foo();
        System.out.println("f.myBar.barNum is " + f.myBar.barNum);
        f.changeIt(f.myBar);

        System.out.println("f.myBar.barNum after changeIt is now " + f.myBar.barNum);

    }
}

[Stephan van Hulst]

Welcome to CodeRanch!

Please tell us first what output you would have expected and why.