What is an object? (Page 238) In C++, an object is just a variable, and the purest definition is "a region of storage" (this is a more specific way of saying, "an object must have a unique identifier," which  in the case of C++ is an u…

1.2.1 package com.qiusongde; import edu.princeton.cs.algs4.Point2D; import edu.princeton.cs.algs4.StdDraw; import edu.princeton.cs.algs4.StdOut; import edu.princeton.cs.algs4.StdRandom; public class Point2DClient { public static void main(String[] ar…

Data Abstraction Hiding implementation Data/Object Anti-Symmetry Objects hide their data behind abstractions and expose function that operate on that data. Data structure expose their data and hava no meaningful functions. Procedural code(code using…

DATABASESYSTEM CONCEPTS SIXTH EDITION Abraham Silberschatz Yale University Henry F. KorthLehigh University S. SudarshanIndian Institute of Technology, Bombay Data Abstraction For the system to be usable, it must retrieve data efficiently. The need fo…

All Objective-C programs are composed of the following two fundamental elements: Program statements (code): This is the part of a program that performs actions and they are called methods. Program data: The data is the information of the program whic…

里氏代换原则(Liskov Substitution Principle, LSP) 1 什么是里氏代换原则 里氏代换原则是由麻省理工学院(MIT)计算机科学实验室的Liskov女士,在1987年的OOPSLA大会上发表的一篇文章<Data Abstraction and Hierarchy>里面提出来的,主要阐述了有关继承的一些原则,也就是什么时候应该使用继承,什么时候不应该使用继承,以及其中的蕴涵的原理.2002年,我们前面单一职责原则中提到的软件工程大师Robert C. Martin,…

在疯狂java中,多态是这样解释的: 多态:相同类型的变量,调用同一个方法时,呈现出多中不同的行为特征, 这就是多态. 加上下面的解释:(多态四小类:强制的,重载的,参数的和包含的) 同时, 还用人这解释: 多态性是Java面向对象的一个重要机制,本文将向您详细介绍Java语言中多态性的实现原理和方法,通过多态一点带出更多Java面向对象有趣而实用的知识. 多态性是面向对象程序设计代码重用的一个重要机制,我们曾不只一次的提到Java多态性.在Java运行时多态性:继承和接口的实现一文中,我们曾详…

database applications: – Banking System,– Stock Market,– Transportation,– Social Network,– Marine Data Analysis,– Criminal Analysis and Control,– Now, BIG DATA.... • Develop a good database system:– Effectively organize data (database design).– Effic…

variable point to code variable expression tree data structure lamda expression anonymous function 原文 Newcomers to LINQ often find expression trees difficult to grasp. In this post I hope to show that the subject is not quite as difficult as it might…

1.格式与命名规范1.1 缩进 使用Tab缩进,而不是空格键1.2 换行 每行120字符 if,for,while语句只有单句时,如果该句可能引起阅读混淆,需要用" {"和"}"括起来,否则可以省略. //错误,需要使用花括号{}括起来 if (condition) if(condition) doSomething(); else doSomething(); 1.3 命名规则 不允许使用汉语拼音命名 遇到缩写如XML时,仅首字母大写,即loadXmlDocume…