17.1 Object-oriented featuresPython is an object-oriented programming language, which means that it provides features that support object-oriented programming.It is not easy to define object-oriented programming, but we have already seen some of its…

8.1. Class Declarations 8.1.1. Class Modifiers 8.1.1.1. abstract Classes 8.1.1.2. final Classes 8.1.1.3. strictfp Classes 8.1.2. Generic Classes and Type Parameters 8.1.3. Inner Classes and Enclosing Instances 8.1.4. Superclasses and Subclasses 8.1.5…

16.1 TimeAs another example of a user-defined type, we’ll define a class called Time that records the time of day. The class definition looks like this: class Time(object): """Represents the time of day. attributes: hour, minute, second &qu…

15.1 User-defined typesWe have used many of Python’s built-in types; now we are going to define a new type. As an example, we will create a type called Point that represents a point in two-dimensional space.In mathematical notation, points are often…

Let’s look more closely at one of the simplest Java programs you can have—one that simply prints a message to console: public class FirstSample { public static void main(String[] args) { System.out.println("We will not use 'Hello, World!'"); } }…

最近在学习使用Scala语言做项目,感觉这门语言实在是太优美了!作为一个本科数学.研究生机器学习专业的混合人才(哈哈),这门语言真的是满足了普通计算机编程(告诉计算机怎么做)和函数式编程(告诉计算机做什么)的所有幻想.学了半个多月,根本停不下来!先来做个总结: 语法简洁,往往比Java少至少一半的代码量.比如: 支持自动类型判断,可以省去很多类型标志. e.g.  val x = 2 用伴生对象来生成类,省去new的麻烦.e.g. val cat = Cat("Hello Ketty"…

<Effective Java>目录摘抄. 我知道这看起来很糟糕.当下,自己缺少实际操作,只能暂时摘抄下目录.随着,实践的增多,慢慢填充更多的示例. Chapter 2 Creating and Destroying Objects Consider static factory methods instead of constructors Consider a builder when faced with many constructor parameters Enforce the s…

Members that are const or reference must be initialized. Similary, members that are of a class type that does not define a default constructor also must be initialized. class ConstRef{ public: ConstRef(int ii); private: int i; const int ci; int & ri;…

The fundamental ideas behind classes are data abstraction and encapsulation. Data abstraction is a programming technical that relies on the separation of interface(declaration) and implementation(definition) A class designer desings and implements a…

Building Maintainable Software-java篇之Separate Concerns in Modules   In a system that is both complex and tightly coupled, accidents are inevitable. -Charles Perrow's Normal Accidents theory in one sentence Guideline: • Avoid large modules in order to…