J-Fundamentals

Hello World in J

Every programming journey starts with Hello World. In J, this is remarkably concise—just a string expression that outputs to the screen.

The Code

Create a file named hello.ijs:

1

'Hello, …

Variables and Types in J

In most languages, variables hold single values—a number, a string, a boolean. In J, the fundamental unit of data is the array. Even a single number is an array (a zero-dimensional one). Understanding …

Operators in J

In most programming languages, “operators” are a small, fixed set of infix symbols like +, -, and ==. In J, what other languages call operators are called verbs, and they are first-class …