编写一个student类，计算平均成绩

编写Student类，包括学生的学号no，姓名name和成绩score三个基本属性，以及一个求所有学生总成绩的静态数据sum及学生人数number。使用构造函数对3个学生的基本信息进行初始化，使用静态方法计算3名学生的平均成绩ave。Student类中的方法根据需要自行定义。

自己照着改改

public class Student {
    
    private String no;
    private String name;
    private double score;
    
    public static double sum;
    public static int number;
    
    public Student(String no,String name,double score) {
        this.no = no;
        this.name = name;
        this.score = score;
        
        sum += score;
        number ++;
    }
    
    public String getNo() {
        return no;
    }

    public String getName() {
        return name;
    }

    public double getScore() {
        return score;
    }

    public static double average() {
        return sum / number;
    }
    
    public static void main(String[] args) {
        Student s1 = new Student("1","a",100);
        Student s2 = new Student("2","b",90);
        Student s3 = new Student("3","c",80);
        
        System.out.println("Average score is:"+Student.average());
    }

}