JavaScript Basics Quiz

Which keyword is used to declare a variable in JavaScript?

• dim

• declare

• var

• int

How do you write “Hello World” in an alert box?

• alertBox("Hello World");

• msgBox("Hello World");

• alert("Hello World");

• msg("Hello World");

What is the correct syntax to output "Hi" to the browser console?

• print("Hi")

• console.print("Hi")

• console.log("Hi")

• log.console("Hi")

Which of these is a correct JavaScript data type?

• integer

• decimal

• object

• real

What will be the output of `2 + "2"` in JavaScript?

• 4

• 22

• Error

• NaN

Which method selects an element with a specific class?

• getElementByClassName

• getElementsByClassName

• queryElementClass

• classSelector

Which method is used to add a click event to a button?

• addEvent

• onClick()

• addEventListener()

• clickEvent()

What does `innerHTML` do in JavaScript?

• Gets/sets HTML content of an element

• Gets the tag name

• Gets CSS style

• Reads element attribute

What will `document.getElementById("demo")` return?

• All demo tags

• A single element with ID "demo"

• Null always

• An array

Which property can change the background color of a div in JavaScript?

• bgColor

• style.backgroundColor

• color

• background