4 Excellent Free Books to Learn J

Last Updated on May 5, 2023

The J programming language, developed in the early 1990s by Kenneth E. Iverson and Roger Hui, is an array programming language based primarily on APL (also by Iverson). It’s available on a wide variety of computers and operating systems. J is distinguished by its simple and consistent rules, a large set of built-in capabilities, powerful facilities for defining new operations, and a general and systematic treatment of arrays.

The J system provides: an engine for executing J; various front ends that provide user interfaces to the J engine; a library, written in J, that provides an IDE (interactive development environment), numerous tools, utilities, demos, tutorials; and online documentation.

J is a very terse array programming language, and is most suited to mathematical and statistical programming, especially when performing operations on matrices. It has also been used in extreme programming and network performance analysis.

J supports function-level programming via its tacit programming features.

J is free and open-source software published under the GNU General Public License version 3.

1. Learning J by Roger Stokes

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

The book is organized as follows. Part 1 is a basic 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.

Read the book

2. User Manual

The User Manual documents the J programming environment, standard library and various other topics such as DLL calls and ODBC.

The manual has sections on:

• J System Overview
• Command Line Parameters
• Directory Paths
• Starting J – Details
• Starting J – Profile Errors
• Binaries – Shared Libraries – Directories
• Standard Library

Read the book

3. J for C Programmers by Henry Rich

The purpose of this book is to help experienced C programmers see what J is all about.

This book will tell you enough about J for you to use it as a language for developing serious applications, but it’s about more than learning the J language: it’s also about ‘thinking big’ in programming, and how programming in J is fundamentally different from programming in C.

C programs deal intimately with scalars (single numbers and characters), and even when they combine those scalars into arrays and structures, the operations on the arrays and structures are defined by operations on the scalars. To ensure that each item of an array is operated on, loops are created that visit each element of the array and perform a scalar operation on the element.

Read the book

4. Primer & The J Dictionary

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.

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.

Read the primer

All books in this series: