The GDK (Groovy Development Kit) provides a number of helper methods, operators, utilities, and additional classes.
Some of these are methods added to every Java class, like "each", and some are more obscure.
Collections
Groovy adds tons of helpful methods that allow easier manipulation of collections, arrays, or any Iterable:
sort—Sorts the collection (if it is sortable).
findAll—Finds all elements that match a closure.
collect—An iterator that builds a new collection.
inject—Loops through the values and returns a single value (similar to the concept of “reduce”).
each—Iterates through the values using the given closure. ...
