Adding item to array in java?

Question

I have an array, defined as below:

String[] letters = {"ab", "cd", "ef", "gh"};

How would I go about adding an item to this array?

Just take a look here: [enter link description here][1] [1]: http://stackoverflow.com/questions/2843366/how-to-add-new-elements-to-an-array — Mirko, May 05 '14 at 09:29
have a look at [this][1] [1]: http://stackoverflow.com/a/2843371/2764279 — earthmover, May 05 '14 at 09:30

score 2 · Answer 1 · answered May 05 '14 at 09:33

2

1.Arrays are fixed in size

2.Before declaring an array we should know the size in advance.

3.We cannot add anything dynamically to an array once we declare its size.

I recommend you to go for collection framework like List or Set where you can increase the size dynamically

answered May 05 '14 at 09:33

Naveen

535
3
14

Check out this http://stackoverflow.com/questions/5061721/how-can-i-dynamically-add-items-to-a-java-array – Naveen May 05 '14 at 09:42

Abimaran Kugathasan · Answer 2 · 2014-05-05T09:41:46.033

1

Java arrays having static size. One you define the size of a array, it can't grow further dynamically.

Your letters array has a size of 4 element. So, you can't add more element to it.

Use ArrayList instead

List<String> letters = new ArrayList(); // Java 7 and upper versions
letters.add("ab");
letters.add("cd");
....// You can add more elements here

edited May 05 '14 at 09:41

answered May 05 '14 at 09:29

Abimaran Kugathasan

31,165
11
75
105

@HayleyvanWaas : Check updated answer with example – Abimaran Kugathasan May 05 '14 at 09:32
1

Downvoter: Please specify the reason for that. – Abimaran Kugathasan May 05 '14 at 09:35
Seeing the list of duplicates of this question, I think the reason for the downvote is pretty clear. There's absolutely no need to have another copy with the same answers and examples on SO. – SvenT23 May 05 '14 at 09:49
@SvenT23 : It can't be done by closing the question instead. That's the recommended way of doing. – Abimaran Kugathasan May 05 '14 at 09:51
I thought the recommended way of doing things was referring to the duplicate with the flag to close it, not answering the question again :) According to my knowledge, that solves her problem and gets rid of this copy faster. – SvenT23 May 05 '14 at 09:57

score 1 · Answer 3 · answered May 05 '14 at 09:33

By using this type of array initialization you cannot simply add more elements.

String[] letters = {"ab", "cd", "ef", "gh"};

Could be paraphrased as:

String[] letters = new String[4];
letters[0] = "ab";
letters[1] = "cd"; 
letters[2] = "ef";
letters[3] = "gh";

So, your array's length is only 4. To add more elements you should somehow copy you array to a bigger one and add elements there. Or just use ArrayList which does the hard work for you when capacity is exceeded.

score -1 · Answer 4 · answered May 05 '14 at 09:33

-1

This is not possible without a workaround like http://www.mkyong.com/java/java-append-values-into-an-object-array/

try ArrayList, List, Map, HashMap or something like this instead

answered May 05 '14 at 09:33

Xavjer

8,838
2
22
42

Adding item to array in java?

4 Answers4