design patterns elements of reusable object oriented software

reasons such as the need to modify the original code of the software, may introduce errors in the old code, or we will have to refactor the entire functionality, and the original code needs to be tested again. This has a special impact on our entire system, which also fully shows the coupling of the system if too high, will greatly increase the later expansion, maintenance. In order to solve this problem, people have summed up the principle of opening and closing. The fundamental solution to th

in Iofile.However, virtual inheritance is not commonly used because: 1. Virtual inheritance increases the cost of space and time. 2. Virtual inheritance can be very complex (writing costs) because the virtual base class, either indirectly or directly inherited, must assume the initialization of these bases, regardless of how many layers of inheritance are. Please rememberMultiple inheritance is more complex than single inheritance. It can lead to new ambiguity and the need for

the outside world.In General , process-oriented development is relatively easy, but it is not easy to deal with changes, object-oriented development is difficult, but it can better deal with the ever-changing world. Therefore, the modern software needs object-oriented devel

If the principle of open-end is object-oriented design, then the dependency reversal principle is one of the main implementation mechanisms of object-oriented design, which is the concrete implementation of system abstraction. The

The opening and closing principle is the first cornerstone of object-oriented reusable design, and it is the most important object-oriented design principle. The opening and closing pri

); parent.goSchool(); parent.pay(); parent.getBook(); parent.goHome(); }}? Usually the beginning of the school report is very happy, because after all, just finished years, received a lot of lucky money, but also waiting to go to school flowers quickly. But Xiao Ming too much love, too little money, rather die than report, to Xiao Ming himself to the school report too difficult, Xiao Ming's parents had to replace Xiao Ming to register. Instead of Xiao Ming to enrol

coupling degree, reducing The effect of class changes on other classes.The principle of synthetic multiplexing is to use some existing objects in a new object to make them part of the new object through association relationships (including combinatorial relationships and aggregation relationships), and the new object to invoke the method of the existing

The so-called design principles or design patterns are nothing more than those created on the premise of object-oriented. The premise of object-oriented is abstraction. The three featur

First, we need to know what the mode is: In short: while people constantly discover problems and find solutions to problems in their own environments, discovering different problems actually involves a common nature. These essence is what we call models. Therefore, the model is representative. In the Object-Oriented field, the earliest modeling method research was published in 1995 by Gang of Four (gof, Eri

Object-oriented analysis is a process of acquiring and understanding user's needs, analyzing the problem domain, confirming and establishing the conceptual model of problem area. and object-oriented design (OOD) is from the perspective of computer technology, the analysis of

http://blog.csdn.net/lovelion/article/details/7537584In order to satisfy the principle of opening and closing, abstract design is needed for the system, and abstraction is the key to open and close principle. In programming languages such as Java, C #, you can define a relatively stable abstraction layer for the system, and move the different implementation behaviors to the specific implementation layer. In many o