J is a dialect of APL, a formal imperative language. Because it is imperative, 句子 in J may also be called an instruction,與may be executed to produce a result. Because it is formal與unambiguous it can be executed mechanically by a computer,與is refore called a programming language. Because it shares analytic properties of mamatical notation, it is also called an analytic language.

APL originated in an attempt to 提供consistent notation for teaching與analysis of topics related to application of computers,與developed through its use in a variety of topics, and its implementation in computer systems [1-5].

J is implemented in C (as 詳見 Hui [6]), and is ported to a number of different host computer systems. effect of specific host is minimal,與communication with it is confined to single 外部連接詞 詳見附錄 A. See help files for or host facilities such as 視窗.

Introduction in this book 提供s guidance to beginners. References [7-9] use J 在exposition of 各類 mamatical topics.