动态阵列列表大小

Question

How can I set size of a dynamic array with Java?

I tried setsize(...) with the array variable but not working. How can I do this?

Answer 1

array size needs to be fixed while initialization, use List instead and then have array from List using toArray()

For example:

List<Integer> listOfInt = new ArrayList<Integer>(); //no fixed size mentioned
listOfInt .add(1);
listOfInt .add(2);
listOfInt .add(3);
//now convert it to array 
Integer[] arrayOfInt = list.toArray(new Integer[listOfInt .size()]);

Answer 2

Your title is confusing. Are you using an ArrayList or an Array.
An ArrayList expands and shrinks as needed each time you call the add , remove method respectively (or any other add/remove variant). There is no need to manage its size yourself.

A list is initialized as follows:

List<Integer> lst = new ArrayList<Integer>();

Now you have a list where you can add a virtual infinite amount of elements.

An array needs its size on initialization which cannot be changed without reinitializing.