Arguments - Call by Value(Java Version)

TestRef

package com.ado.java;

public class TestRef {

    public static void main(String[] args)
    {
        ValueObject vo1 = new ValueObject("A", 1);
        System.out.println("after vo1: " + vo1.getName()); //=A

        changeValue1(vo1);
        System.out.println("after changeValue1: " + vo1.getName());
        //=A1, changed

        changeValue2(vo1);
        System.out.println("after changeValue2: " + vo1.getName());

        ValueObject v2 = new ValueObject("C", 3);
        ValueObject v3 = new ValueObject("D", 4);
        v2 = v3;
        System.out.println("after v2=v3");
        System.out.println("v2= "+ v2.getName());//=D
        System.out.println("v3= "+ v3.getName());//=D
        v3.setName("C1");
        System.out.println("after v3 setnameTo C1");
        System.out.println("vo2= "+ v2.getName());//=C1
        System.out.println("vo3= "+ v3.getName());//=C1
    }

    private static void changeValue1(ValueObject vo1) {
        vo1.setName("A1");
    }

    private static void changeValue2(ValueObject vo1) {
        vo1 = new ValueObject("B", 2);
        System.out.println("inside changeValue2: "+ vo1.getName());
    }
}

class ValueObject {

    public ValueObject() {}

    public ValueObject(String name, int id)
    {
        this.name = name;
        this.id = id;
    }

    private String name;
    private int id;

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

understand the variable itself and the value of variable.....