J (programming language)

The J programming language, developed in the early 90's by Ken Iverson and Roger Hui, is a synthesis of APL (also by Iverson) and the FP and FL functional programming languages created by John Backus (of FORTRAN, ALGOL, and BNF fame).

To avoid the problems faced by the special character set of APL, J requires only the basic ASCII character set, resorting to the use of dot and colon characters to extend the meaning of the basic characters available.

Being an array programming language, J is very terse and powerful, and is often found to be useful for mathematical and statistical programming, especially when performing operations on matrices.

Like the original FP/FL languages, J supports function-level programming (also known as higher-order functional programming), via its tacit programming features (note that function-level programming is not the same as functional programming).

Unlike most languages that support object-oriented programming, J's flexible hierarchichal namespace scheme (where every name exists in a particular locale) can be effectively used as a framework for both class-based and instance-based object oriented programming.

J is an non-von Neumann programming language that nevertheless allows the programmer to use von Neumann programming style when desired.

Hello world

Examples

J is an extremely powerful language, and its programs can be very terse but even more cryptic. Here is a one-liner implementation of the quicksort algorithm:

(No, it is not Function-level programming

Related programming languages:  APL, FP, FL, NGL, K