Java构造方法的应用

1.无参数的构造方法和有参数的构造方法

//无参数

package test;

public class People {
public String name;
public String sex;
public int age;
People (){

}

}

//有参数

package test;

public class People {
public String name;
public String sex;
public int age;
People (String name,String sex,int age){
this.name=name;

this.sex=sex;

this.age=age;
}
public static void main(String[] args){

People p=new People("老王","男",20);
System.out.println(p.name+p.sex+p.age);
}

}