class Person { private String name; private int age; public Person() { } public Person(String name, int age) { this.name = name; // this.age = age;//构造方法中不能直接赋值，应该调用setAge方法 setAge(age); } public void setName(String name) { this.name = name; } public String getName() { return name; } public void setAge(int age) { //在赋值之前先判断年龄是否合法 if (age > 130 || age < 0) { this.age = 18;//不合法赋默认值18 } else { this.age = age;//合法才能赋值给属性age } } public int getAge() { return age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; }}public class Test2 { public static void main(String[] args) { Person p1 = new Person(); //p1.name = "小红"; //编译错误 //p1.age = -45; //编译错误 p1.setName("小红"); p1.setAge(-45); System.out.println(p1); Person p2 = new Person("小白", 300); System.out.println(p2); }} |
老师，构造方法Person中，不使用this.age=age;是否因为需要用setAge(age)；来限制输入的年龄
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