无参构造方法和有参构造方法:

 参构造方法要结合get xxx()方法和set xxx()方法使用
 例如以创建一个学生类,该学生的属性(成员变量)有姓名,性别,年龄;行为是吃,睡觉,学习

无参构造方法

class Student{
    private String name;
    private String gender;
    private int age;
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getName() {
        return name;
    }
 
    public void setGender(String gender) {
        this.gender = gender;
    }
 
    public String getGender() {
        return gender;
    }
 
    public void setAge(int age) {
        this.age = age;
    }
 
    public int getAge() {
        return age;
    }
    public String eat(String food){
        return "吃"+food;
    }
    public void sleep(){
        System.out.println("学累了就睡觉!!!");
    }
    public String  study(String className){
        return "正在学习"+className;
    }
}
public class StudentTest {
    public static void main(String[] args) {
        Student s = new Student();
        s.setName("梁海博");
        s.setGender("男");
        s.setAge(22);
        System.out.println("学生的姓名:"+s.getName()+"\n"+"学生的性别:"+s.getGender()+"\n"+"学生的年龄:"+s.getAge());
        String result = s.eat("香蕉");
        System.out.println(result);
        s.sleep();
        System.out.println(s.study("JavaEE"));
 
    }
}

有参构造方法:

//有参构造方法
class Student1{
    private String name;
    private String gender;
    private int age;
 
    public Student1(String name,String gender,int age){
        this.name=name;
        this.gender=gender;
        this.age=age;
    }
     public String getName(){
        return name;
     }
     public String getGender(){
        return gender;
     }
     public int getAge(){
        return age;
     }
 
    public void eat(){
        System.out.println("吃辣条!!");
    }
    public void sleep(){
        System.out.println("睡大觉!!!");
    }
    public void study(){
        System.out.println("学JavaEE!!!!");
    }
}
public class StudentTest1 {
    public static void main(String[] args) {
        Student1 s = new Student1("梁海博","男",22);
        System.out.println("学生的姓名:"+s.getName()+"\n"+"学生的性别:"+s.getGender()+"\n"+"学生的年龄:"+s.getAge());
        s.eat();
        s.sleep();
        s.study();
    }
}