I have an array, defined as below:
String[] letters = {"ab", "cd", "ef", "gh"};
How would I go about adding an item to this array?
4 Answers
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
1 Comment
Naveen
Check out this stackoverflow.com/questions/5061721/…
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.
Comments
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
answered May 5, 2014 at 9:29
Abimaran Kugathasan
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5 Comments
Abimaran Kugathasan
@HayleyvanWaas : Check updated answer with example
Abimaran Kugathasan
Downvoter: Please specify the reason for that.
SvenT23
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.
Abimaran Kugathasan
@SvenT23 : It can't be done by closing the question instead. That's the recommended way of doing.
SvenT23
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.
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
Listinstead?List