Article “Understanding the problem domain is the hardest part of programming”
It is very difficult to learn more than one thing at a time
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As a student studying software development, it is therefore very difficult to learn how to code a problem when you don’t fully understand the problem when expressed in plain language
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In a professional setting, it will be much harder to build a solution if you don’t fully understand the problem that you are being asked to solve
Both situations can be addressed in one of two ways:
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Make the problem domain easier
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Get better at understanding the problem domain
JavaScript Ch. 3 - Object Literals
property: a variable that is part of an object
method: a function that is part of an object (ergo, the value of a method is always a function)
key: the unique name assigned to a value within an object. An object cannot have two keys with the same name
- Within an object, each key is separated from its value using a colon. The pair is then followed by a comma
keyName: value,
The properties or methods of an object can be accessed using dot notation. Properties can also be accessed using square brackets
JavaScript Ch. 5 - Document Object Model
The Document Object Model (DOM) specifies how browsers should create a model of an HTML page and how JavaScript can access and update the contents of a web page while it is in the browser window.
DOM tree used to specify the way a browser should structure a model of a webpage (DOM)
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begins with a document node that represents the entire page and corresponds to the document object
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every element, attribute, and piece of text in the HTML is then represented by its own DOM node
Application Programming Interface (API) lets programs and scripts talk to each other
To access and update the DOM tree:
- Locate the node that represents the element you want to work with
- Use its text content, child elements, and attributes
nodeList is the collection of nodes that is returned when a method can return more than one node
- A live nodeList is updated when a script updates the page
-A static nodeList does not reflect changes made when a script updates the page
There are two possible ways to add and remove content from a DOM tree:
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The innerHTML Property provides new content as a string
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DOM Manipulation involves creating element and text nodes and then attaching or removing them from the DOM tree
Cross-Site Scripting Attacks (XSS) are a risk when using innerHTML, as an attacker may be able to place malicious code into the website
There are several precautions that can be taken to protect against XSS:
- Filter or Validate Input
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Limit where user content goes
- Do not place user content in script tags, html comments, tag names, attributes, or CSS values