Array vs array list

Array vs array list

• 1.
  Array vs ArrayList JAVA
• 2.
  Comparison Points 1. Declaration 2. Resizable 3.Performance 4. Traversal 5. Primitives 6. Length 7. Type-Safety 8. Adding elements 9. Multi-dimensional
• 3.
  Declaration Array ArrayList int arr[]= new int[10] ArrayList<Type>arrL=new ArrayList<Type>();
• 4.
  Resizable Array ArrayList Static insize Dynamic in size Fixed length data structure Each ArrayList object has instance variable capacity which indicates the size of the ArrayList. Can not change the length after creating the Array object. As elements are added to an ArrayList its capacity grows automatically.
• 5.
  Performance Array ArrayList resize() N.A.Automatic resize will slow down the performance uses temporary array to copy elements from the old array to new array. ArrayList is internally backed by Array during resizing as it calls the native implemented method. add() or get() Almost same performance , as for ArrayList object these operations run in constant time.
• 6.
  Traversal Array ArrayList Loops Loops+ Fail fast iterators
• 7.
  Primitives Array ArrayList can containboth primitive data types as well as objects. can not contains primitive data types (like int , float , double) it can only contains Object
• 8.
  Length Array ArrayList .length .size()
• 9.
  Type Safety Array ArrayList Arrayis a homogeneous data structure , thus it will contain objects of specific class or primitives of specific data type. Type Safety through Generics
• 10.
  Adding Elements Array ArrayList Assignmentoperator .add()
• 11.
  Multidimensional Array ArrayList Can bemulti dimensional Always single dimensional.