Learning J

(seventh draft, March 2002, still unfinished)

J Software Home Page

This book is meant to help the reader to learn the computer-programming language J.

The book is intended to be read with enjoyment by both the beginning programmer and the experienced programmer alike. The only prerequisite is an interest on the part of the reader in learning a programming language.

The emphasis is on making the J language accessible to a wide readership. Care is taken to introduce only one new idea at a time, to provide examples at every step, and to make examples so simple that the point can be grasped immediately. Even so, the experienced programmer will find much to enjoy in the radical simplicity and power of the J notation.

The scope of this book is the core J language common to the many implementations of J available on different computers. The coverage of the core language is meant to be relatively complete, covering (eventually) most of the J Dictionary.

(Hence the book does not cover topics such as graphics, plotting, GUI, and database access covered in the J User Guide. It should also be stated what the aims of the book are not: neither to teach principles of programming as such, nor to study algorithms, or topics in mathematics or other subjects using J as a vehicle, nor to provide definitive reference material.)

The book is organised as follows. Part 1 is an elementary introduction which touches on a variety of themes. The aim is to provide the reader, by the end of part 1, with an overview and a general appreciation of the J language. The themes introduced in Part 1 are then developed in more depth and detail in the remainder of the book.

Chapters with titles shown as links are in place. The others will be eventually.

Part 1: Getting Acquainted	1: Basics 2: Lists and Tables 3: Defining Functions 4: Scripts and Explicit Functions
Part 2: Arrays	5: Building Arrays 6: Indexing 7: Ranks
Part 3: Defining Functions: Verbs	8: Composition 9: Trains of Verbs 10: Tacit Verbs Continued 11: Explicit Verb Definition
Part 4: Defining Functions: Operators	12: Explicit Operators 13: Tacit Operators 14: Gerunds 15: Tacit From Explicit
Part 5: Structural Functions	16: Rearrangements 17: Patterns of Application 18: Sets and Classes
Part 6: Numerical and Mathematical Functions	19: Numbers 20: Scalar Functions 21: Factors and Polynomials 22: Vectors and Matrices 23: Calculus
Part 7: Names and Objects	24: Names and Locales 25: Object Oriented Programming
Part 8: Facilities	26: Script Files 27: Representations and Conversions 28: Data Files 29: Global Parameters 30: Debug
Part 9: Various	31: Evaluating Expressions (in Slow Motion)
Appendices	A1: Collected Terminology

These web pages are also available in a single downloadable zip file. There is a version in PDF format on Skip Cave's web page.

Copyright © Roger Stokes 2002. This material may be freely reproduced, provided that this copyright notice, including this provision, is also reproduced.