reading-notes

Class 6 - Problem Domain, Objects, and the DOM

Object Basics

1. How would you describe an object to a non-technical friend you grew up with?
   • My dear friend, an object is a collection of related information. When paired together, they’re called properties and methods.
2. What are some advantages to creating object literals?
   • Creating object literals is a quick, flexible way to create single objects and can be input easily into code.
3. How do objects differ from arrays?
   • Arrays are a sequential list of values, while objects can store a much larger collection of data and can be multi-dimensional.
4. Give an example for when you would need to use bracket notation to access an object’s property instead of dot notation.
   • If an object property name is held in a variable, then bracket notation would be used instead of dot notation (which wouldn’t work).
5. Evaluate the code below. What does the term this refer to and what is the advantage to using this?
   • It refers to the current object where the this resides, which in this case is dog. This is useful if you’re using the same code to create multiple objects and don’t want to change the object name inside the code each time.

const dog = {
  name: 'Spot',
  age: 2,
  color: 'white with black spots',
  humanAge: function (){
    console.log(`${this.name} is ${this.age*7} in human years`);
  }
}

Introduction To The DOM

1. What is the DOM?
   • “The Document Object Model (DOM) is a programming interface for web documents. It represents the page so that programs can change the document structure, style, and content. The DOM represents the document as nodes and objects; that way, programming languages can interact with the page.” https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model/Introduction
2. Briefly describe the relationship between the DOM and JavaScript.
   • “The code is written in JavaScript, but uses the DOM to access the document and its elements. The DOM is not a programming language, but without it, the JavaScript language wouldn’t have any model or notion of web pages, HTML documents, SVG documents, and their component parts. The document as a whole, the head, tables within the document, table headers, text within the table cells, and all other elements in a document are parts of the document object model for that document. They can all be accessed and manipulated using the DOM and a scripting language like JavaScript.” https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model/Introduction