Programming Groovy 2

6.6 Iterating Over Map

Groovy has added quite a few convenience methods to maps.[26] We can iterate over a ​Map​, just like how we iterated over an ​ArrayList​ (see Section 6.2, ​Iterating Over an ArrayList​).

​Map​ has a flavor of the ​each​ and ​collect​ methods.

Map’s each Method

Let’s look at an example of using the ​each​ method:

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

langs.each { entry ->
  println "Language $entry.key was authored by $entry.value"
}

The output from the previous code is as follows:

Language C++ was authored by Stroustrup
Language Java was authored by Gosling
Language Lisp was authored by McCarthy

If the closure we ...