Nov 1, 2011 · String[] myArray = myArrayList.toArray(new String[0]); But it less effective: the string array is created twice: first time zero-length array is created, then the real-size array is created, filled and returned. So, if since you know the needed size (from list.size()) you should create array that is big enough to put all elements.

Oct 1, 2008 · If you look, Arrays ISN'T returning a true java.util.ArrayList. It's returning an inner class that implements the required methods, but you cannot change the memebers in the list.

Jul 22, 2019 · I have an ArrayList with values like "abcd#xyz" and "mnop#qrs". I want to convert it into an Array and then split it with # as delimiter and have abcd,mnop in an array and xyz,qrs in another array.

There are two styles to convert a collection to an array: either using a pre-sized array (like c.toArray (new String [c.size ()])) or using an empty array (like c.toArray (new String [0]). In older Java versions using pre-sized array was recommended, as the reflection call which is necessary to create an array of proper size was quite slow.

Is there a command in java for conversion of an ArrayList into a object array. I know how to do this copying each object from the arrayList into the object array, but I was wondering if would it be...

Mar 21, 2011 · According to Joshua Bloch in Effective Java, preallocating the array harms performance. Provide a zero-length array instead. stockList.toArray(new String[0])

How do I convert an array to a list in Java? I used the Arrays.asList() but the behavior (and signature) somehow changed from Java SE 1.4.2 (docs now in archive) to 8 and most snippets I found on t...

Apr 5, 2009 · The problem in this code here is the use of a zero length array as the argument. The ArrayList.toArray source code shows that if the contents will fit, the original array will be used.

Oct 28, 2010 · How might I convert an ArrayList<String> object to a String [] array in Java?

Jan 27, 2010 · In Java how do you convert a ArrayList into a two dimensional array Object[][]? From comments: I will describe you the problem with more details: an XML file includes a list of contacts (e.g. na...