Java构造方法的使用

• Student类：

package com.zws04;
/*
 * 构造方法的使用：
 */
public class Student {
    private String name;
    private int age;

    public Student(){

    }

    public Student(int age) {
        this.age = age;
    }

    public Student(String name) {
        this.name = name;
    }

    public Student(String name,int age) {
        this.name = name;
        this.age = age;
    }

    public void show() {
        System.out.println("姓名是："+name+",年龄是："+age);
        System.out.println("-------------------");
    }
}

• StudentDemo类：

package com.zws04;

public class StudentDemo {
    public static void main(String[] args) {
        Student stu = new Student();
        stu.show();
        Student stu1 = new Student(28);
        stu1.show();
        Student stu2 = new Student("张大壮");
        stu2.show();
        Student stu3 = new Student("张大壮",28);
        stu3.show();        
    }
}

结果：
    姓名是：null,年龄是：0
    -------------------
    姓名是：null,年龄是：28
    -------------------
    姓名是：张大壮,年龄是：0
    -------------------
    姓名是：张大壮,年龄是：28
    -------------------