为什么change方法里面不调用this也能把数组里面的值改变了，str则要调用this才能改变

Question

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[]) {

    str = "test ok";

    ch[0] = 'g';

}

}

Answer 1

引用传递和值传递，集合传递的都是引用，非集合传递的是值