package stu;

import java.util.Scanner;

public class student {
    public static void main(String[] args){
        //从键盘输入三个学生的五门成绩
        St s[] = new St[3];
        s[0].info(0);
        s[1].info(1);
        s[2].info(2);
    }
}

class St{
    //学生五门课，学号和成绩
    String Name;
    public String getName(String name) {
          return Name = name;
         }
   
    int Num;
    public int getNum(int num) {
          return Num = num;
         }
   
    double Chinese;
    public double getChinese(double chinese) {
          return Chinese = chinese;
         }
   
    double Math;
    public double getMath(double math) {
          return Math = math;
         }
    double English;
    public double getEnglish(double english) {
          return English = english;
         }
   
    double Phyics;
    public double getPhyics(double phyics) {
          return Phyics = phyics;
         }
   
    double Chemistry;
    public double getChemistry(double chemistry) {
          return Chemistry = chemistry;
         }
   
    public void info(int i){
        St s = new St();
            System.out.println("请输入第" + i+1 +"个学生的信息");
                //输入学生的名字
            System.out.println("姓名：");
            Scanner n = new Scanner(System.in);
            String name = n.nextLine();
            s.Name = s.getName(name);
            //输入学生的学号
            System.out.println("学号：");
            Scanner b = new Scanner(System.in);
            int num = b.nextInt();
            s.Num = s.getNum(num);
            //输入学生的语文成绩
            System.out.println("Chinese：");
            Scanner c = new Scanner(System.in);
            double chinese = c.nextInt();
            s.Chinese = s.getChinese(chinese);
            //输入学生的数学成绩
            System.out.println("Math：");
            Scanner d = new Scanner(System.in);
            double math = d.nextInt();
            s.Math = s.getMath(math);
            //输入学生的英语成绩
            System.out.println("English：");
            Scanner e = new Scanner(System.in);
            double english = e.nextInt();
            s.English = s.getEnglish(english);
            //输入学生的物理成绩
            System.out.println("Phyics：");
            Scanner f = new Scanner(System.in);
            double phyics = f.nextInt();
            s.Phyics = s.getPhyics(phyics);
            //输入学生的化学成绩
            System.out.println("Chemistry：");
            Scanner g = new Scanner(System.in);
            double chemistry = g.nextInt();
            s.Chemistry = s.getChemistry(chemistry);
            }
}
为什么不能运行？求大神指点。

兄弟，我问了一下老师，他说是因为数组对象和普通对象的区别，但我还是不太清楚其中的具体情况。如果你搞清楚了记得顺便跟我说一声。

兄弟，我明白了，在用数组之前还要实例化一下数组元素。如在用  s[0].info(i)之前还要加一句  s[0] = new St();这样就可以了！！