Java 类继承详解：示例解析

Java\u4e2d\u7684\u7c7b\u7ee7\u627f\u662f\u4e00\u79cd\u91cd\u8981\u7684\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u6982\u5ff5\uff0c\u5b83\u5141\u8bb8\u4e00\u4e2a\u7c7b\u7ee7\u627f\u53e6\u4e00\u4e2a\u7c7b\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u51e0\u4e2a\u4f8b\u5b50\uff0c\u7528\u4e8e\u751f\u52a8\u8be6\u7ec6\u8bf4\u660e\u4e2d\u8bcd\u7c7b\u7ee7\u627f\uff1a\n\n1\u3002\u4eba\u7c7b\u548c\u5b66\u751f\u7c7b\u7684\u7ee7\u627f\u5173\u7cfb\uff1a\n\njava\nclass Person {\n protected String name;\n protected int age;\n\n public Person(String name, int age) {\n this.name = name;\n this.age = age;\n }\n\n public void introduce() {\n System.out.println("My name is " + name + " and I am " + age + " years old.");\n }\n}\n\nclass Student extends Person {\n private String school;\n\n public Student(String name, int age, String school) {\n super(name, age);\n this.school = school;\n }\n\n public void study() {\n System.out.println("I am studying at " + school + ".");\n }\n}\n\npublic class Main {\n public static void main(String[] args) {\n Student student = new Student("John", 18, "ABC College");\n student.introduce(); // Output: My name is John and I am 18 years old.\n student.study(); // Output: I am studying at ABC College.\n }\n}\n\n\n\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cStudent\u7c7b\u7ee7\u627f\u4e86Person\u7c7b\uff0c\u5b83\u7ee7\u627f\u4e86Person\u7c7b\u7684\u5c5e\u6027\uff08name\u548c\u4ea7age\uff09\u548c\u65b9\u6cd5\uff08introduce()\uff09\u3002Student\u7c7b\u8fd8\u6709\u81ea\u5df1\u7684\u52a0\u591a\u5c5e\u6027\uff08school\uff09\u548c\u65b9\u6cd5\uff08study()\uff09\u3002\u901a\u8fc7\u7ee7\u627f\uff0cStudent\u7c7b\u53ef\u4ee5\u91cd\u7528Person\u7c7b\u7684\u4ee3\u7801\u5e76\u52a0\u5165\u81ea\u5df1\u7684\u7279\u5b9a\u529f\u80fd\u3002\n\n2\u3002\u52a8\u7269\u7c7b\u548c\u72fc\u7c7b\u7684\u7ee7\u627f\u5173\u7cfb\uff1a\n\njava\nclass Animal {\n protected String name;\n\n public Animal(String name) {\n this.name = name;\n }\n\n public void eat() {\n System.out.println(name + " is eating.");\n }\n}\n\nclass Dog extends Animal {\n public Dog(String name) {\n super(name);\n }\n\n public void bark() {\n System.out.println(name + " is barking.");\n }\n}\n\npublic class Main {\n public static void main(String[] args) {\n Dog dog = new Dog("Buddy");\n dog.eat(); // Output: Buddy is eating.\n dog.bark(); // Output: Buddy is barking.\n }\n}\n\n\n\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cDog\u7c7b\u7ee7\u627f\u4e86Animal\u7c7b\uff0c\u5b83\u7ee7\u627f\u4e86Animal\u7c7b\u7684\u5c5e\u6027\uff08name\uff09\u548c\u65b9\u6cd5\uff08eat()\uff09\u3002Dog\u7c7b\u8fd8\u6709\u81ea\u5df1\u7684\u52a0\u591a\u65b9\u6cd5\uff08bark()\uff09\u3002\u901a\u8fc7\u7ee7\u627f\uff0cDog\u7c7b\u53ef\u4ee5\u91cd\u7528Animal\u7c7b\u7684\u4ee3\u7801\u5e76\u52a0\u5165\u81ea\u5df1\u7684\u7279\u5b9a\u529f\u80fd\u3002\n\n3\u3002\u56fe\u5f62\u7c7b\u548c\u77e9\u5f62\u7c7b\u7684\u7ee7\u627f\u5173\u7cfb\uff1a\n\njava\nclass Shape {\n protected double area;\n\n public Shape() {\n this.area = 0;\n }\n\n public void calculateArea() {\n System.out.println("Area: " + area);\n }\n}\n\nclass Rectangle extends Shape {\n private double length;\n private double width;\n\n public Rectangle(double length, double width) {\n this.length = length;\n this.width = width;\n }\n\n public void calculateArea() {\n area = length * width;\n System.out.println("Rectangle Area: " + area);\n }\n}\n\npublic class Main {\n public static void main(String[] args) {\n Rectangle rectangle = new Rectangle(5, 10);\n rectangle.calculateArea(); // Output: Rectangle Area: 50.0\n }\n}\n\n\n\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cRectangle\u7c7b\u7ee7\u627f\u4e86Shape\u7c7b\uff0c\u5b83\u7ee7\u627f\u4e86Shape\u7c7b\u7684\u5c5e\u6027\uff08area\uff09\u548c\u65b9\u6cd5\uff08calculateArea()\uff09\u3002Rectangle\u7c7b\u8fd8\u6709\u81ea\u5df1\u7684\u52a0\u591a\u5c5e\u6027\uff08length\u548cwidth\uff09\u548c\u65b9\u6cd5\uff08calculateArea()\uff09\u3002\u901a\u8fc7\u7ee7\u627f\uff0cRectangle\u7c7b\u53ef\u4ee5\u91cd\u7528Shape\u7c7b\u7684\u4ee3\u7801\u5e76\u52a0\u5165\u81ea\u5df1\u7684\u7279\u5b9a\u529f\u80fd\u3002\n\n\u901a\u8fc7\u8fd9\u4e9b\u4f8b\u5b50\uff0c\u4f60\u53ef\u4ee5\u770b\u5230\u4e2d\u8bcd\u7c7b\u7ee7\u627f\u7684\u5b9e\u9645\u5e94\u7528\u548c\u597d\u5904\u3002\u5b83\u63d0\u4f9b\u4ee3\u7801\u91cd\u7528\u7684\u80fd\u529b\uff0c\u5e76\u5141\u8bb8\u5b50\u7c7b\u52a0\u5165\u81ea\u5df1\u7684\u7279\u5b9a\u529f\u80fd\u3002