5. 传值还是传引用

package s02.e05;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
@NoArgsConstructor
@Getter
@Setter
public class Person {
    private Integer id;
    private String personName;
    public Person(String personName) {
        this.personName = personName;
    }
}

package s02.e05;
public class TestTransferValue {
    public void changeValue1(int age) {
        age = 30;
    }
    public void changeValue2(Person person) {
        person.setPersonName("xxx");
    }
    public void changeValue3(String str) {
        str = "xxx";
    }
    public static void main(String[] args) {
        TestTransferValue test = new TestTransferValue();
        int age = 20;
        test.changeValue1(age);
        System.out.println("age----" + age);
        Person person = new Person("abc");
        test.changeValue2(person);
        System.out.println("personName-----" + person.getPersonName());
        String str = "abc";
        test.changeValue3(str);
        System.out.println("String-----" + str);
    }
}