①、为何报错构造方法Person（int 。。。

①、为何报错构造方法Person（int ,String,String）未定义？

②、为啥构造方法必须有返回类型否则程序报错？

谢谢！

package com.imooc.person1;

public class Test {

public static void main(String[] args) {

// TODO 自动生成的方法存根

Person one=new Person(29,"金","男");

System.out.println("姓名：one.name 性别：one.sex 年龄：one.age");

System.out.println(one);

one.toString();

}

}

package com.imooc.person1;

public class Person {

private String name;

private String sex;

private int age;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getSex() {

return sex;

}

public void setSex(String sex) {

this.sex = sex;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public void person() {

}

public void person(int age,String name, String sex) 

//为何要加返回值类型才不会报错

{

this.setName(name);

this.setSex(sex);

this.setAge(age);;

}

public String toString() {

return "姓名："+this.getName()+"性别："+this.getSex()+"年龄："+this.getAge();

}

}