JavaScript

Annotations:

• JavaScript is typeless language. The variables doesn't have type , but their values do.

1. DATA TYPES

   Annotations:

   • JavaScript have 6 data types , 5 primitive  types and only 1 reference type.
   1. primitive types
      1. number
      2. string
      3. null
      4. undefined
      5. boolean
   2. Object

      Annotations:

      • Object is the only one reference type. It means that it is copied by reference. We pass a reference as an argument to a function ,like pointers in c/c++.
      • Set of properties. The fields and the methods are properties.
      1. predefined objects
         1. Math
         2. Number
         3. String
         4. document
         5. window
         6. arguments
      2. JSON

         Annotations:

         • JavaScript Object Notation. It is data format used in JS.
      3. ASSOCIATIVE ARRAYS

         Annotations:

         • Every object in JS is associative array. It means that its properties can be accessed that way = obj.["property"]
         • Associative array doesn't have methods length , indexOf ,etc..