dom manipulation

Question 1

What is the className property of element objects?

Answer 1

Used to access or change the class of an element

Question 2

How do you update the CSS class attribute of an element using JavaScript?

Answer 2

var $hotButton = document.querySelector('.hot-button');
Access the node for the class and store in a variable

$hotButton.className = ‘hot-button cold’
Use the className method of the variable used to access the node and assign a new value

Question 3

What is the textContent property of element objects?

Answer 3

Used to access the text content of an element, to update or change.

Question 4

How do you update the text within an element using JavaScript?

Answer 4

var $clickCount = document.querySelector('.click-count');
Use the query selector to select a class and set to a variable

$clickCount.textContent = ‘Clicks: ‘ + timesClicked;
use the textContent method on the variable and assign a value to change it

Question 5

Is the event parameter of an event listener callback always useful?

Answer 5

No

Question 6

Would this assignment be simpler or more complicated if we didn’t use a variable to keep track of the number of clicks?

Answer 6

Complicated, would have to find a different way to constantly update the number

Question 7

Why is storing information about a program in variables better than only storing it in the DOM?

Answer 7

javascript is easier to use, and avoid using the dom if we can help it