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Clue barNote barWrite a calculator programSee Appendix 1Why is movable type printing called one of the four great inventions in ancient China?As shown in Figure 1-1 1. Words can be directly replaced and maintainable.2. The completed words can be reused. 3. Words can be expanded freely 4. The characters can be arranged horizontally and vertica ...

Strategy mode Define a series of algorithms, close them one by one, and make them replace each other. Example: processing store promotion types prePrice - Treatment preheating price onSalePrice - Deal with big price promotion backPrice - Processing return price freshPrice - Deal with early taste price askPrice - Distribute RFQ logic Implem ...

Singleton mode Singleton mode: the object of a class is obtained multiple times in the code. The results obtained multiple times are the same object. This object is a singleton object. Common singleton mode Since a singleton does not allow multiple duplicate objects, and generally objects are created through constructors, na then the ...

Structural design pattern Structural design patterns focus on how to combine classes or objects into larger and more complex knot structures to simplify design 1, Appearance mode Appearance mode: it provides a more advanced unified interface for a group of complex subsystem interfaces, which makes the results of the subsystem easier to a ...

Analysis of Agent Model 1. What is proxy mode What is the agent mode? First of all, a simple example is Zhang San (user) wants a ticket for a concert but he has no channel to buy it. Then his friend Li Si (agent) said he can buy tickets for a concert (agent method).In some cases, one object is not suitable or cannot directly refer to another ...

In the process of software development, some objects in the application may make different behaviors according to different situations. We call this kind of object stateful object, and one or more dynamically changing attributes that affect the behavior of the object state. When stateful objects interact with external events, their inter ...

Introduction: Factory Pattern is one of the most commonly used design patterns in Java. This type of design pattern is a creation pattern, which provides the best way to create objects. As the name suggests, a factory is the place where products are produced. The factory mode includes simple factory, static factory, factory method, abstract fa ...

Four arithmetic problems Four operations are realized through the interpreter mode, such as calculating the value of a+b-c. specific requirements: First enter the form of the expression, such as a+b+c-d+e, which requires that the letters of the expression cannot be repeated.Then enter the values of a, b, c, d and e respectively.Finally, the o ...

Most office workers have the habit of sleeping in. They are very nervous at work every morning, so many people will solve the breakfast problem in a convenient way in order to get more sleep. Some people may have pancakes for breakfast. They can add eggs or sausages to the pancakes, but no matter how "overweight", they are stil ...

Initial knowledge of dynamic proxy 1 Agent mode 1.1 Purpose: The purpose of proxy mode is to provide a proxy for other objects to control access to this object. Use a proxy to wrap the object and replace the original object with the proxy object. Any call to the original object is made through the proxy. The proxy object decides whether a ...