Is there an easy way to convert from array to arrayList?

Question

I am writing a class that has an arrayList that holds objects as a data member and for one of the methods in this class I have to convert it into a basic array. To achieve this I created a new array and used the .toArray() method. Now at the end of this method I have to put it back into the original arrayList. It appears that array doesn't have a .toArrayList(). I'm just wondering what the most simple way to convert would be. Thanks for any help.

Edit: forgot to say what the arrayList was holding (objects)

Arrays.asList? You can then use new ArrayList(Arrays.asList(...)) or anInstanceOfList.addAll(Arrays.asList(...)) depending on your needs — MadProgrammer
– MadProgrammer, Commented Mar 13, 2015 at 2:46
All sounds very inefficient. Why do you have to convert from ArrayList to an array? — jarmod
– jarmod, Commented Mar 13, 2015 at 2:49

MattGarnett · Accepted Answer · 2015-03-13 02:46:22Z

2

new ArrayList<Element>(Arrays.asList(array))

answered Mar 13, 2015 at 2:46

MattGarnett

6455 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Elliott Frisch · Accepted Answer · 2015-03-13 02:47:07Z

1

You don't mention the array type, but assuming it's an array of object(s) (as opposed to primitives) you could use Arrays.asList(T...) like

String[] arr = {"Hello", "World"};
List<String> al = new ArrayList<>(Arrays.asList(arr));

answered Mar 13, 2015 at 2:47

Elliott Frisch

202k20 gold badges166 silver badges265 bronze badges

2 Comments

MadProgrammer Over a year ago

(I believe the OP wants an instance of ArrayList at the end ;))

yitzih Over a year ago

Will this work? since asList really just returns a List view of the array?

Collectives™ on Stack Overflow

Is there an easy way to convert from array to arrayList?

2 Answers 2

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related