Java increase array by X size

Question

I need an array that I can determine its size from the start and if it has no more empty spaces then increase its size by X. For example:

int arrayS         


        

Answer 1

ArrayList or Vector is resizing by itself, so you don't need to do it manually at all. The drawback is that they use object types, not primitives. You are encouraged to use ArrayList as Vector is deprecated.

If you need automatically resizable primitive arrays use Apache Commons Primitives.

If you want to resize your array manually you should allocate new array and copy data and change reference like this:

int[] array_new = new int[size_new];
System.arraycopy(array, 0, array_new, 0, array.length);
array = array_new;

Or use Arrays.copy() as other answers suggests.