DOM-events

Question 1

Why do we log things to the console?

Answer 1

To see what’s going on without having to find the issue later.

Question 2

What is the purpose of events and event handling?

Answer 2

They notify code of interesting changes.

Question 3

Are all possible parameters required to use a JavaScript method or function?

Answer 3

Not sure.

Question 4

What method of element objects lets you set up a function to be called when a specific type of event occurs?

Answer 4

addEventListener

Question 5

What is a callback function?

Answer 5

A function passed into another function as an argument.

Question 6

What object is passed into an event listener callback when the event fires?

Answer 6

The event object

Question 7

What is the event.target? If you weren’t sure, how would you check? Where could you get more information about it?

Answer 7

The target event property returns the element that triggered the event. Where the interaction took place.

Question 8

What is the difference between these two snippets of code?

Answer 8

element. addEventListener(‘click’, handleClick)
element. addEventListener(‘click’, handleClick())

In the 1st, the 2nd argument is the function named handleClick, in the 2nd argument, the 2nd argument is being called. We’re passing a function definition.