Answers for "arryas vs arraylist"

Difference between Array vs ArrayList

Arrays are fixed size
ArrayList's size auotomatically adjusted
Arrays can hold primitives and object
ArrayList can hold only objects
Arrays can be multi dimensional
ArrayList cannot be multi-dimentional
Array is a build in data structure
ArrayList is implementing class of List interface in Collection framework

arraylist vs vector in java

ArrayList is not thread safe
Vector is thread safe/syncronized
ArrayList is faster than Vector
Both allow duplicate values and keep ordering
Both are implementations of List interface