Icon

Hello World in Icon

Every programming journey starts with Hello World. Let’s write our first Icon program and get a glimpse of this unique language with its goal-directed evaluation.

The Code

Create a file named …

Variables and Types in Icon

Icon takes a relaxed approach to variables and types. Variables don’t need declarations — just assign a value with := and the variable springs into existence. The type belongs to the value, not …

Operators in Icon

Operators in Icon look familiar at first glance — +, -, *, / work just as you’d expect. But Icon’s operators have a twist: every operator is an expression that can either succeed …

Control Flow in Icon

Control flow determines the order in which your program’s statements run. Most languages build this on top of boolean values: a condition is either true or false, and that decides which branch …

Functions in Icon

In Icon, the unit of reusable code is the procedure. There is no separate function keyword - a procedure is defined with procedure…end, and whether it behaves like a “function” …