package string_int;

public class Fun_ref {
	
	public static void main(String[] args) {
     Ref_test ref_test=new Ref_test();
     System.out.println("ref_test.s1="+ref_test.s1);
     fun_ref(ref_test);
     System.out.println("ref_test.s1="+ref_test.s1);

	}
	 public static void fun_ref (Ref_test ref_out){
		Ref_test ref_in=new Ref_test();
		ref_in.s1="in";
		//ref_out.s1="out";
		ref_out=ref_in;//漏洞!!ref_out 指向ref_in ,
		//那么當函數(shù)退出后,ref_out就會自動指向原來的堆!!!
		System.out.println("fun_ref()    ref_out.s1="+ref_out.s1);
		}

}

 class Ref_test {
	String s1="test";
 }