 It is available in Java as the "ArrayList" type and in Python as the "list" type.A dynamic array may be implemented by a data structure consisting of an array "A" of items, of some length "N", together with a number "n" ≤ "N" representing the positions within the array that have been used so far.With this structure, random accesses to the dynamic array may be implemented by accessing the same cell of the internal array "A", and when "n" Goodrich and Tamassia, 1.5.2 Analyzing an Extendable Array Implementation, pp.