Written by Paul Hudson     @twostraws It's very common in iOS to want to create complex objects only when you need them, largely because with limited computing power at your disposal you need to avoid doing expensive work unless it's really needed. S…

1. Variables (1) Three ways to define variables: 1) val refers to define an immutable variable; scala> val x = x: Int = scala> x*x res4: Int = scala> res4 + # use result as a value res6: Int = scala> res4 + res6 res7: Int = scala> x = # x i…

Lazy initialization - It decreases the cost of initializing a class or creating an instance, at the expense of increasing the cost of accessing the lazily initialized field. Depending on what fraction of lazily initialized fields eventually require i…

Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question asked. Students may write correct answers in different forms which makes grading very ha…

Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question asked. Students may write correct answers in different forms which makes grading very ha…

Problem Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question asked. Students may write correct answers in different forms which makes grading…

  Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 3721   Accepted: 1290 Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question ask…

Object copy An object copy is an action in computing where a data object has its attributes copied to another object of the same data type. An object is a composite data type in object-oriented programming languages. The copying of data is one of the…

原文:http://lazyfoo.net/tutorials/SDL/22_timing/index.php Timing 计时 Last Updated 3/10/14 Another important part of any sort of gaming API is the ability to handle time. In this tutorial we'll make a timer we can restart. 对于任何游戏API,另一个重要的部分是能够处理时间参量.在这个…

坏味道--冗余类(Lazy Class) 特征 理解和维护类总是费时费力的.如果一个类不值得你花费精力,它就应该被删除. 问题原因 也许一个类的初始设计是一个功能完全的类,然而随着代码的变迁,变得没什么用了. 又或者类起初的设计是为了支持未来的功能扩展,然而却一直未派上用场. 解决方法 没什么用的类可以运用 将类内联化(Inline Class) 来干掉. 如果子类用处不大,试试 折叠继承体系(Collapse Hierarchy) . 收益 减少代码量 易于维护 何时忽略 有时,创建冗余类是为…