【正文】 r different mentality and functionality, it’s a little early to tell which one is better. 2. Smart Phone OS . Android The system architecture of Android consists of 5 layers, which are Linux Kernel, Android Runtime, Libraries, Application Framework and Applications, from bottom to top. Android provides core services like security, memory management, process management, work stack and drivers, basing on Linux . Being the abstract layer between software and hardware, the layer of Linux Kernel hides the implementing details of hardware and provides integrated services for upper layer. Dalvik virtual machine and Java core libraries are included in the layer of Android Runtime, providing most functions in Java core libraries. The layer of Libraries contains a class of C/C++ libraries for Android ponents. Those libraries are integrated by the layer of Application Framework and then provided to developers. The layer of Application Framework provides all kinds of modules for program initialization to simplify the use of ponents, allowing developers do whatever they want and provide services for other softwares, under the limitation of security, of course. Mainstream applications are located in the layer of Application, 河北大學(xué) 21012屆本科畢業(yè)生外文文獻(xiàn)翻譯 3 including , SMS, calendar, Google map, Web browser and contacts. Users interact directly with this layer [1] [2]. The latest version of Android, Android Froyo, puts on some new features. They are: 1. Support Flash , enables user to watch flash on the phone. 2. V8 JavaScript engine in web browser leads to faster Inter data transportation. 3. Big advance in work sharing. You can use the phone as a 3G NIC,or convert 3G signal to WiFi. 4. Automatically software update. 5. Softwares can be setup in SD card to extend file storages. . iPhone iPhone OS is consist of 4 abstract layers: Core OS, Core Service, Media and Cocoa Touch respectively. Layers of Core OS and Core Service are designed in C language to handle core system services, enabling developers to perform file access, sockets calling and data handling. CFNetwork and SQLite are also parts of these 2 layers. The layer of Media, according to its name, this layer is used to control video and audio, as well handle 2D and 3D images. The Open GLES Quratz part of the layer is coded with C language, while the part of CoreAudio and CoreAnimation is Objective C based. The layer of Cocoa Touch builds a basic framework for all kinds of programs in iPhone. Most programs run in Cocoa Touch layer, and it’s surely Objective C based [3] [4]. The latest iPhone OS is iOS 4. It includes the following new features: classification. This feature enables user to place sorted softwares into different documents, making it clearer to manage. 2. Email integration. One account is for all s from different providers. 3. iBook, originally from iPad, is built in iOS. 4. A brand new Apple Game Center makes iPhone a tremendous entertainment platform. . Android vs. iPhone Being the top 2 smart phone OSs, we’re sure that both Android and iPhone have their own advantages and disadvantages. Now let’s take a look at each of them, and see what unique feature they have. 河北大學(xué) 21012屆本科畢業(yè)生外文文獻(xiàn)翻譯 4 Android Froyo fully support multitask, which means you can listen to music while writing blog. And iOS 4, officially announced to be ‘multitasked’, is in fact a play of concept. Only a few of softwares which are authorized by Apple can run ‘simultaneously’, whose principle is much easier that multitask:when an application is switched out, its current state is saved and then the system just closes it. And when it’s switched in, we’re back to the previous snapshot [5] [6] [7]. During the publication of Android Froyo, Google announced it has ‘the most fluent web browser’,because the use of V8 JavaScript engine. V8 is a brand new engine, designed for running big size JavaScript application. In some kind of tests, V8 is much faster than JScript from Inter Explorer, SpiderMonkey from Firefox and JavaScriptCore from Safari. It all owe to 3 key parts of V8, they’re fast attribute access, dynamic code generation, effective trash cleaning. . Fast Attribute Access JavaScript is a kind of dynamic language, which means attributes