12. Introduction

Variables are (perhaps unsurprisingly), items that can change. Essentially a variable is a “box” that can hold a value. Groovy is a “dynamic language” in that it allows you to easily store and manipulate variables regardless of their value. This places it in similar company to Python and Ruby but, as a child of Java, Groovy can also operate as a “typed language”. In typed languages we can specify the data type (e.g. a number or piece of text) of the variable.

Groovy lets us work in both language modes - dynamic and typed - and this flexibility makes it that much easier to use.