reading-notes

Problem Domain, Objects, and the DOM

Understanding the problem

• familiarty can take away from the problem domain and make learning easier
• writing code is like putting together a jigsaw puzzle. if you take one problem at a time putting together the code or picture is easier.
• understanding the problem is a big part of writing code
• if you can do that it makes thing much easier
• cut out cases and narrow your focus to one part of the problem

Object Literals

• if a variable is part of an object it is called a property

property - properties tell us about the object

• if a function is part of an object it is called a method

method - Methods reresent tasks that are associated with an object

key - properties and methods have a name and value that is called a key

the value of a property can be a string, boolean, and array , or another object.

the value of a method is always a function

Creating an Object

Literal notaion is the easiest and most popular way to create objects

• the object is the curly braces and their content -seperate each key from its value by using a colon
• seperate each property and method with a comma. (but not after the last value)
• use the this keyword to tell the method you are using the properties of this object

  Acessing an object and DOT notation

• you can access the properties or methods of an object using dot notation
• you can also access properties using square brackets
• to access a property or method of an object you use the name of the object followed by a period
• then the name of the property or method you want to access

Dom

• Document Object Model

• when a browser loads a page it creates a model
• the model is called a DOM tree
• it has different nodes

The Document Node

• when you access any element or attribute or text it has to go through the document node

Element Node

to access the dom tree you start by looking at elements

• once you find the elements you want then you access all other nodes if you want