3.4. Working with strings

Considering how widely used strings are, many languages—including Java—provide few language features to make them easier to use. Scripting languages tend to fare better in this regard than mainstream application languages, so Groovy takes on board some of those extra features. This section examines what’s available in Groovy and how to make the most of the extra abilities.

Groovy strings come in two flavors: plain strings and GString s. Plain strings are instances of java.lang.String, and GStrings are instances of groovy.lang.GString. GStrings allow placeholder expressions to be resolved and evaluated at runtime. Many scripting languages have a similar feature, usually called string interpolation, but it’s more primitive than the GString feature of Groovy. Let’s start by looking at each flavor of string and how they appear in code.