Timeline for answer to Java map.get(key) - Is there a way to automatically call put(key) and return if the key doesn't exist? by Roger Lindsjö

11 events

when toggle format	what		by	license	comment
Mar 6, 2022 at 13:54	history	edited	Roger Lindsjö	CC BY-SA 4.0	Clarified what is returned
Dec 4, 2016 at 11:12	history	edited	Roger Lindsjö	CC BY-SA 3.0	Java 8 standard and lazy methods
Nov 21, 2016 at 15:50	comment	added	Roger Lindsjö		You probably want `computeIfAbsent` as shown by @itake
Nov 21, 2016 at 12:15	comment	added	efinal		it doesn't work is the value itself is supposed to be a collection. as what I wanted is add an empty collection AND RETURN IT so that I can add items into that collection.
Nov 13, 2015 at 4:12	comment	added	yelliver		java.util.Map has putIfAbsent from JDK 8, not only ConcurrentMap.
Jul 11, 2014 at 12:47	history	edited	Roger Lindsjö	CC BY-SA 3.0	Fix description from comments.
Jul 5, 2014 at 1:47	comment	added	Saad Malik		@user802421 is right--this will return null if the value is inserted.
Apr 4, 2013 at 0:09	vote	accept	Sridhar Sarnobat
Dec 1, 2011 at 21:45	comment	added	Christian Semrau		Note that this forces you to create a new object, even if there is already one available in the map. If you really only create a `new Object()`, this may be negligible.
Nov 30, 2011 at 23:31	comment	added	user802421		Returns: the previous value associated with the specified key, or null if there was no mapping for the key
Nov 30, 2011 at 22:48	history	answered	Roger Lindsjö	CC BY-SA 3.0