think in java读书笔记--字符串

每当把String对象作为方法的参数传递时，都会复制一份引用。而该引用所指的对象其实一直待在单一的物理位置上，从未动过。

public static void main(String[] args) {
		String a = "abc";

<pre name="code" class="java"><span style="white-space:pre">		</span>System.out.println(a);

String b = upper(a); // 传递的是String对应的一个引用副本，复制一份引用System.out.println(b);System.out.println(a);Person p = new Person();p.setName("zzzzzzz");System.out.println(p);Person q = changePerson(p); // 传递的是p的引用地址值System.out.println(q);System.out.println(p);}private static String upper(String str) {return str.toUpperCase();}private static Person changePerson(Person person) {person.setName("aaaaaaaaaaa");return person;}}class Person {private String name;public Person() {}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "Person [name=" + name + "]";}

//运行结果：

abc
ABC
abc
Person [name=zzzzzzz]
Person [name=aaaaaaaaaaa]
Person [name=aaaaaaaaaaa]