1. 声明一个变量person指向一个引用对象,

    然后将这个person添加到集合list中,

 然后将变量person指向null,

 问:list中添加的person变成null了吗?

import java.util.ArrayList;
import java.util.List;

public class TestRef {

    public static void main(String[] args) {

        Person p = new Person("张三");
        List<Person> list = new ArrayList<Person>();
        list.add(p);
        p = null;

        for (Person person : list) {
            System.out.println(person); // Person [name=张三]
        }

    }
}

class Person {
    private String name;

    public Person(String name) {
        super();
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Person [name=" + name + "]";
    }
}
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