JavaScript and the DOM

Today’s topics

• More practice with functions and arrays
• Using JS in the browser
• The DOM: the Document Object Model
• DOM manipulation with JS
• Events in JS

🎯 Project: JavaScript Calculator

UPDATE: This assignment is due Thursday, Feb 1 at 9am. 🌺

NOTE: Your calculator does not have to look like the green one. It needs the same buttons, but you can add your own style. Steps 1 & 2 are HTML and CSS, so start there. Then, move on to adding the event listener to one button, then all the numbers, and so on.

🦉 Code & Notes

• JS and the DOM notes
• Animal Clicking Code Pen Example

🔖 Reference Shelf

• CSS-Tricks: What Is the DOM?
• MDN Introduction to Events
• MDN Element Events -> this is where you can see the events that are defined for elements (like “click” or “mouseover”)
• MDN Event Reference -> this is a huge list of all the available events, useful mainly to get an idea of what’s possible
• DOM Manipulation with Vanilla JS
• How JS Event Delegation Works
• Chapters 13-15 of Eloquent JavaScript

⭐️ EXTRA/TMI

This resource is really not at all necessary to understand or do the project, but if you want to know more about the concept of tree structures in computer science, check out this piece from Vaidehi Joshi’s BaseCS blog series. She is awesome! There is also a thoroughly delightful accompanying BaseCS podcast with the equally amazing Saron Yitbarek.

• BaseCS blog series: How Not to be Stumped by Trees

And here is more info about what is happening when a browser renders a page – very enlightening, although not strictly necessary at this stage:

• About the browser rendering engine
• How browser rendering works

This is a good explanation about how JS events “bubble” up the chain of elements on the page:

• JS Event Bubbling and Capturing

If you would like to know more about the JavaScript Event Loop and how it works, I highly recommend this resource. Don’t miss the video of the conference talk that goes along with it – it’s excellent:

• Loupe: Visualizing the JS Event Loop