String作为函数参数时，传入的是值，不是地址

写个小程序试下：

public class Example {

String str = new String("good");

char[] ch = { 'a', 'b', 'c' };

public static void main(String args[]) {

Example ex = new Example();

ex.change(ex.str, ex.ch);

System.out.print(ex.str + " and ");

System.out.print(ex.ch);

}

public void change(String str, char ch[]) {

System.out.println("str:"+str+", ch:"+ch);
str = "test ok";

ch[0] = 'g';

}
}

运行结果：

str:good, ch:[C@de6ced
good and gbc