Programming Groovy 2

6.5 Using the ​Map​ Class

Java’s ​java.util.Map​ is useful when we want to work with an associative set of key and value pairs. Groovy makes working with ​Map​s simple and elegant with the use of closures. Creating an instance of ​Map​ is also simple, because we don’t need to use ​new​ or specify any class names. Simply create pairs of values:

langs = ['C++' : 'Stroustrup', 'Java' : 'Gosling', 'Lisp' : 'McCarthy']

println langs.getClass().name

Let’s confirm in the output the class of the collection we created:

java.util.LinkedHashMap

This example creates a hash map of some languages as keys, and their authors as values. The keys are separated from their values using a colon (​:​), and ...