String,StringBuffer做参数

package jia;
public class 参数传递
{


public static void main(String[] args)
{
// TODO Auto-generated method stub
        StringBuffer a=new StringBuffer("abc");
        change(a);
        System.out.println(a);
}
static void change(StringBuffer a)
{

a.append("a"); //输出为abca

a=new StringBuffer("a");//输出为abc

}

}

String做参数

package jia;
public class 参数传递
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
String a=new String("abc");
        change(a);
        System.out.println(a);
}
static void change(String a)
{
a+="a";//输出为abc

a=new String("a");//输出为abc
}


}