Java 学生类：定义、封装方法和测试示例

public class Student {\n private int sid;\n private String name;\n private int age;\n private int[] scores;\n\n public Student(int sid, String name, int age) {\n this.sid = sid;\n this.name = name;\n this.age = age;\n this.scores = new int[5];\n }\n\n public void printInfo() {\n System.out.println("学号：" + sid);\n System.out.println("姓名：" + name);\n System.out.println("年龄：" + age);\n System.out.println("成绩：");\n System.out.println("Java：" + scores[0]);\n System.out.println("HTML：" + scores[1]);\n System.out.println("CSS：" + scores[2]);\n System.out.println("MySQL：" + scores[3]);\n System.out.println("JavaScript：" + scores[4]);\n }\n\n public void inputScores(int java, int html, int css, int mysql, int javascript) {\n scores[0] = java;\n scores[1] = html;\n scores[2] = css;\n scores[3] = mysql;\n scores[4] = javascript;\n }\n\n public double calculateAverageScore() {\n int sum = 0;\n for (int score : scores) {\n sum += score;\n }\n return (double) sum / scores.length;\n }\n\n public int getScoreBySubject(String subject) {\n switch (subject) {\n case "Java":\n return scores[0];\n case "HTML":\n return scores[1];\n case "CSS":\n return scores[2];\n case "MySQL":\n return scores[3];\n case "JavaScript":\n return scores[4];\n default:\n return 0;\n }\n }\n}\npublic class Main {\n public static void main(String[] args) {\n Student student = new Student(1001, "张三", 18);\n student.inputScores(80, 75, 90, 85, 95);\n student.printInfo();\n \n double averageScore = student.calculateAverageScore();\n System.out.println("平均成绩：" + averageScore);\n \n int javaScore = student.getScoreBySubject("Java");\n System.out.println("Java成绩：" + javaScore);\n }\n}