JavaScriptオブジェクト指向プログラミング　 例題一覧

Display Objects

Some common solutions to display JavaScript objects are: displaying

1. the Object Properties by name
2. the Object Properties in a Loop
3. the Object using Object.values()
4. the Object using JSON.stringify()

• four displaying Examples
• Stringify Dates
• Stringify Arrays

Accessors(Getters and Setters)

Getters and setters allow you to define Object Accessors (Computed Properties).

• Getter
• Setter
• Methods vs Accessors
• Data Quality
• Object.defineProperty()

object constructor function

Objects of the same type are created by calling the constructor function with the new keyword:

• Constructor Function
• add a property and a method to an object
• add a property to a constructor
• add a method to a constructor
• method of mechod
• Built-in Constructors
• Primitive values are much faster

Prototypes

The JavaScript prototype property allows you to add new properties and add new methods to object constructors:

• add new Property
• add new method

Iterables

Iterable objects are objects that can be iterated over with for..of. Technically, iterables must implement the Symbol.iterator method.

• Iterating Over a String
• Iterating Over an Array
• Iterators
• Home Made Iterable
• object Symbol.iterator
• The Symbol.iterator method is called automatically by for..of. But we can also do it "manually": example

Sets

A JavaScript Set is a collection of unique values. Each value can only occur once in a Set. A Set can hold any value of any data type.

• Set Methods
• Create a Set
  • Passing an Array to new Set()
  • use add() to add values
  • use add() to add variables
  • The forEach() Method
  • The values() Method and key() method
  • The entries() Method

Maps

A Map holds key-value pairs where the keys can be any datatype. A Map remembers the original insertion order of the keys. A Map has a property that represents the size of the map.

• Map methods
• Create a map
• Passing an Array to new Map() constructor
• Create a Map and use Map.set()
• get() method and Map.size
• Map.forEach() and Map.entries()
• Map.keys() and Map.values vs Object as keys
• Map.has() and Map.delete() and Map.cear()

Class

JavaScript Classes are templates for JavaScript Objects.

• class
• inheritance
• getter and setter
• static

Async

To define the executing sequence of fuctions by following techniques.

• functions are executed in the sequence they are called
• callback

  A callback is a function passed as an argument to another function.

• Asynchronous
  • setTimeout
  • Waiting for Intervals
  • Waiting for Files
• Promises

  A Promise is a JavaScript object that links producing code and consuming code

  • Promises object
  • Using Promises
  • Using Promises for wating a file
• async/await

  async makes a function return a Promise await makes a function wait for a Promise.The await keyword can only be used inside an async function.

  • async/await