Js

Question 1

declare and assign variables

Answer 1

var x = 5; // Function-scoped
let y = 10; // Block-scoped
const z = 15; // Block-scoped, immutable

Question 2

user interaction dialogs

Answer 2

alert()
confirm()
prompts()

Question 3

event and event handler

Answer 3

event: action triggered by user and caught by browser
event handler; function that executes events

<input type = “button” value”click” onclick=”function()”/>
function(){alert(“clicked”);}

Question 4

Name common events.

Answer 4

click, mouseover, keydown, load, submit

Question 5

What’s the difference between onclick and addEventListener?

Answer 5

onclick overwrites existing handlers.

addEventListener allows multiple handlers:

Question 6

How do you change an element’s content?

Answer 6

document.getElementById(“demo”).innerHTML = “New content”;