java类private/this的使用

package 类的练习;

public class Person {
    private String name;
    private int age;
    private String sex;
    private String hobby;
    public String getSex() {
    return sex;
  }
  public void setSex(String sex) {
    this.sex = sex;
  }
  public String getHobby() {
    return hobby;
  }
  public void setHobby(String hobby) {
    this.hobby = hobby;
  }
  public void showInfo() {
      System.out.println(this.name+"----"+this.age);
    }
    //name :方法的参数name
    //this.name:当前类的属性name
    public void setName(String name) {
      this.name=name;
    }
    public String getName() {
      return name;
    }
    public void setAge(int age) {
      if(age<0) {
        System.out.println("我滴个乖乖,年龄能成负的?");
        this.age=-1;
        System.out.println("年龄有误！");
      } else if(age>120) {
        System.out.println("人能活那么久?");
        this.age=-1;
        System.out.println("年龄有误！");
      }else {
      this.age=age;
      }
    }
    public int getAge() {
      return age;
    }

}

package 类的练习;

public class TestPerson {

  public static void main(String[] args) {
    Person per=new Person();
    per.setName("张三");
    per.setAge(20);
    per.setSex("男");
    per.setHobby("敲代码");
    System.out.println("名字:"+per.getName());
    System.out.println("年龄:"+per.getAge());
    System.out.println("性别:"+per.getSex());
    System.out.println("爱好:"+per.getHobby());
  }

}