class Value{
    public int i=15;
}
public class Test{
    public static void main(String arg[]){
        Test t=new Test();
        t.first();
    }
    public void first(){
        int i=5;
        Value v=new Value();
        v.i=25;
        second(v,i);
        System.out.println(v.i);
    }
    public void second(Value v,int i){
        i=0;
        v.i=20;
        
        Value val=new Value();
        v=val;
        System.out.println(v.i+""+i);
}}
怎么理解？求解释。