setter 方法由于 this 关键字而给出错误

Question

程序在 setter 方法中抛出错误，可能是由于使用了 this 关键字。为什么会报错呢？

错误：方法调用 setAge(-5)，将字段值设置为“-5”，但预期为“0”。预期：<0>但是是：<-5>。

public class Person {

    private String firstName;
    private String lastName;
    private int age;

    public String getFirstName(){

        return this.firstName;
    }

    public String getLastName(){

        return this.lastName;
    }

    public int getAge(){

        return this.age;
    }

    public void setFirstName(String firstName){

        this.firstName = firstName;
    }

    public void setLastName(String lastName){

        this.lastName = lastName;
    }

    public void setAge(int age){

        **if(age < 0 || age > 100){
            this.age = 0;** *Why this keyword gives an error here?*
        }
       
        this.age = age;
    }
}

Answer 1

将您的设置年龄函数更改为：

public void setAge(int age){

        if(age < 0 || age > 100){
            this.age = 0;
        }
        else
            this.age = age;
       
       
    }

或

public void setAge(int age){

        if(age < 0 || age > 100){
            age = 0;
        }
       
        this.age = age;
    }