Groovy map method of collections

Question

Is there a map method in Groovy? I want to do something like I do with the following Scala snippet:

scala> val l = List(1, 2, 3)
l: List[Int] = List(1, 2, 3)

scala> l.map(_ + 1)
res0: List[Int] = List(2, 3, 4)

score 153 · Accepted Answer · edited Mar 07 '23 at 16:55

153

There is such a method in groovy, it is called collect, for example:

assert [1, 2, 3].collect { it * 2 } == [2, 4, 6]

edited Mar 07 '23 at 16:55

Lifeweaver

answered Jan 19 '11 at 11:21

IttayD

13

assert [1,2,3].collect {it+1} == [2,3,4] – sbglasius Jan 19 '11 at 11:38
94

Quite strange function name for very popular idiom – ruX May 31 '14 at 09:04
22

If you think collect is strange, wait until you come across 'inject' for reduce/fold operation! – Καrτhικ Dec 16 '14 at 11:39
7

I suspect `collect` and `inject` are borrowed from methods by those names in Ruby's Enumerable mixin. – Roy Tinker Apr 28 '16 at 21:20
1

@RoyTinker, is probably correct. Groovy takes some inspiration from Ruby's function names (collect, inject), and its syntax (def, optional parens, braces for closures). – Paul Draper Nov 07 '16 at 19:48
works flawlessly! – Gaurav Feb 16 '22 at 14:51
Thank you from the future – Blundell Nov 29 '22 at 11:27

1 Answers1