Module design

• ini package

data structures

• primitive values: num, booleans, strings

  • immutable and cannot be changed
  • copied "as a whole value"

• arrays and objects are used to group values into a single value

  • arrays - sequence of values

  • objects - dict

    • reference - binding
    • mutable

  • object is stored and copied "by reference"

  • most objects also have a prototype

    • a prototype is another object that is used as a fallback source of properties
    • Object.prototype

JS functions are regular values representing an "action"

• higher-order functions allow us to abstract over actions, not just values
  • pass function values to other functions

OOP

• divide programs into smaller pieces and make each piece responsible for managing its own state

• different pieces interact with each other through interfaces

  • pieces are modeled using objects
  • their interface consists of a specific set of methods and properities

• encapsulation

  • separate interface from implementation

class

• in JS, a class is a kind of function
• a class is an extensible program-code-template for creating objects, providing init values for state (variables) and implementations of behavior (functions)