General - JavaScript basics

Question 1

Q: What is type coercion in JavaScript?

Answer 1

A: Automatic conversion between types (e.g., “5” + 2 → “52”)

Question 2

Q: Common JS variable types?

Answer 2

A: String, Number, Boolean, Undefined, Object

Question 3

Q: Two common string methods in JS?

Answer 3

A: .length, .toUpperCase(), .substring()

Question 4

Q: What does document.getElementById(“demo”) do?

Answer 4

A: Selects the element with id “demo” from the DOM.

Question 5

Q: What’s a JavaScript event handler example for a button?

Answer 5

A: <button>Click Me</button>