J PRIMER

本人汉语水平欠佳，求指正//每周出上一周的正式版以及本周的BUILD版。

(www.jsoftware.com/docs/help803/primer)

START HERE

J is a general purpose, high-level programming language. If you are new to J and want to be a J programmer, this is a good place to start. Even if you have considerable programming experience, there is much that is unique to J, and it is worthwhile to at least skim this book before jumping into the deep end.

J是一种多用途的高级编程语言。如果你刚刚学习J语言并且想要成为一名J语言程序员，这是一个开始的好地方。即使你拥有许多编程经验，J语言也是很独特的，并且你值得在深入研究之前浏览这本书。

WHY J

J is a very rich language. You could study and use it for years, and still consider yourself a beginner. This is in sharp contrast to simpler languages like Basic or Java, where months of concerted study and use would make you an expert. The effort required to become an expert J programmer is closer to that required to become an expert C++ programmer.

J是一门丰富的语言。你可能会持续学习、使用它多年，并且仍然认为自己是一个初学者。这和一些类似于Basic或Java之类的更加简单的只需几个月就能成为专家的语言形成强烈的反差。成为一名J语言专家所要付出的努力不亚于成为一名c++高手。

The good news is that the essence of J is so simple and consistent, that you can quickly learn enough to start solving real and interesting problems.

It is easier to learn enough Basic or Java to solve trivial problems, but it is easier to learn enough J to solve more interesting and challenging problems. And once you have that level of skill under your belt, you are not at the end of the road, but can continue to improve, making yourself a better and more formidable programmer.

但好消息是J语言的本质是简单且一致的。那会使你快速地学会足够的知识以解决真实且有趣的问题。
学习BASIC或JAVA来解决一些小问题可能会简单些，但学习J语言可以去解决更加有趣、有挑战性的问题。只要你有能够达到的那种水平的技能，你就还有可以学习的东西，去继续提高，使你成为一个更好的更加受人尊敬的程序员。

J is particularly strong in the mathematical, statistical, and logical analysis of arrays of data. It is a powerful tool in building new and better solutions to old problems and even better at finding solutions where the problem is not already well understood.

J尤其擅长数学、统计学和对数据的逻辑分析。它是一个找到对于旧问题的新的更好的解决方案甚至是解决尚未被完全理解的问题的有力工具。

As well as being a general purpose programming language, the J system also provides:
·an integrated development environment
·standard libraries, utilities, and packages
·a form designer for your application forms (windows)
·an event-driven graphical user interface to your application
·several methods of interfacing with other programming languages and applications
·rapid application prototyping and development
·royalty-free distribution of run-time versions of your application

和其他的多用途语言一样，J语言也提供了：
·一个集成开发环境（IDE）
·标准库、工程以及软件包
·一个窗体设计器（WINDOWS系统）
·一个事件驱动的GUI
·几个与其他语言及程序的连接方法
·应用程序快速原型设计和开发
·免税的应用程序run-time版本

If you are interested in programming solutions to challenging data processing problems, then the time you invest in learning J will be well spent.

如果你对编程解决有难度的数据处理感兴趣，那么投入时间学习J语言是有价值的。

PURPOSE OF THIS BOOK

The J Dictionary is the authoritative and definitive specification of the J language. It can be used to learn J, but the fact that it covers all of the language concisely, yet completely and rigorously, with more emphasis on the complex than the mundane, does scare some of us away.

J Dictionary 是最权威的最佳的J语言说明书。你可以用它来学习J，事实上它简明的囊括了整个J语言，但尚未完全和严谨，它更加地强调联系而不是平凡的东西，那已经吓走了不少像我们这样的学习者。

This online book provides a kinder, gentler start for beginners. This book takes you along a path in easy steps to the point where you can write an application in J. Along the way you will be introduced to all the key ideas in J by seeing them in simplified and specific contexts. At the end, you will be able to write real programs in J, and you will also be comfortable in using the J Dictionary as a reference for your work as a J programmer. The purpose of this online book is to get you up to speed where you can use the J Dictionary in a manner that makes you wonder why you ever bothered with this simple stuff.

这本在线书为初学者提供了一个更友善、更温和的开始。这本书将引领你走过很长一段路直到你能够用J写出应用程序。在整个过程中，你将通过简单且具体的实例来学习所有的J语言的要点。最终你会写出真正的程序，并且你也能使用J DICTIONARY来为你的项目服务。这本书的目的在于让你更快地到达你可以使用J DICTIONARY的地步，以一种让你想知道你为什么曾经为这种简单的东西困惑的方式。

You should be able to work your way through this book fairly quickly, and at the end you will be an entry-level J programmer. As such, you will have far more programming power at your fingertips than even the most experienced Basic or Java programmer.

你应该可以以你自己的方式快速看完这本书，然后你就是一名初级的J语言程序员了。你就具有了甚至比最有经验的BASIC/JAVA程序员更加强大的编程能力。

YOUR BACKGROUND

This online book assumes that you are familiar with another programming language such as Basic, Java, or C. However, this is not a prerequisite, and you shouldn't have particular problems if J is your first computer language (in fact, congratulations!).

此书假定你熟悉另一种语言，例如BASIC,JAVA,C等等。然而这并不是一个前提，把J当做你的第一门语言你并不会有什么特别的困难（事实上，恭喜你了！）。

Most things can be done in J much as they are done in other languages, and in several areas a topic is introduced just as it would be introduced in other languages. If you are familiar with other languages this makes it easier to follow how it works in J. In some cases there is a much better J way to solve a problem, and that is also covered.

大部分可以在J语言里完成的事情都可以在其他语言里完成。在几个地方，一个话题会被介绍得就像其他语言一样。如果你熟悉其他语言，学习它在J语言中的运行方式会轻松些。在几个实例中，有更好的J语言的解决问题的方案也会被提到。

16/3/28