How does memory allocation of an ArrayList work?

Question

As far as I know, when we are creating an ArrayList:

ArrayList list = new ArrayList(SIZE);

The JVM res

Answer 1

The very first thing I want to correct is, When we are adding new elements into our list, when number of elements reaches 100% of SIZE it reserves a new, contiguous part of memory and copies all of the elements.

New Size of ArrayList will be:

NewSize of ArrayList = (CurrentSize * 3/2) + 1

But going this way is never recommended, if we have idea how much objects needs to be stored then we can use following constructor of ArrayList:-

ArrayList ar = new ArrayList(int initialCapacity);

If our JVM couldn't specify enough contiguous space on heap for the ArrayList, At runtime we'll get

• Runtime error: OutOfMemoryError