1、创建一个对象数组，数组的元素是学生对象，学生的信息包括学号、姓名和成绩(一门课成绩)，求其总人数和平均分。（学生对象不得少于5个）

可以这样创建一个学生对象数组：

class Student {
    String id; // 学号
    String name; // 姓名
    int score; // 成绩
}

Student[] students = new Student[5];
students[] = new Student();
students[].id = "001";
students[].name = "张三";
students[].score = 80;

students[1] = new Student();
students[1].id = "002";
students[1].name = "李四";
students[1].score = 90;

students[2] = new Student();
students[2].id = "003";
students[2].name = "王五";
students[2].score = 70;

students[3] = new Student();
students[3].id = "004";
students[3].name = "赵六";
students[3].score = 85;

students[4] = new Student();
students[4].id = "005";
students[4].name = "钱七";
students[4].score = 95;

然后可以用循环遍历数组，计算总人数和总分数，最后求平均分：

int totalScore = ;
int totalStudents = students.length;
for (int i = ; i < students.length; i++) {
    totalScore += students[i].score;
}
double averageScore = (double) totalScore / totalStudents;

System.out.println("总人数：" + totalStudents);
System.out.println("平均分：" + averageScore);