Introduction to JavaScript

Question 1

What is the console?

Answer 1

It’s a panel that displays messages. A lot of our code is invisible to us by default so if we want to see things we can print or log to the console.

Question 2

What does a semicolon do?

Answer 2

Indicates the end of a line or statement.

Question 3

What are the Primitive Data Types?

Answer 3

String, Number, Object, Boolean, Symbol, Null, Undefined

Question 4

What is Math and name two methods you can call on Math.

Answer 4

Math is a built-in object.

1. Math.floor(x) returns the largest integer less than or equal to x
2. Math.random() returns a random number between 0 and 1.

Question 5

Give two points about let

Answer 5

1. You can declare a variable without assigning an initial value. The value will automatically be undefined.
2. You can reassign the value of the variable

Question 6

Why would you want the ability to reassign values to a variable? For instance, why use let?

Answer 6

One example could be to update user input. Another example could be a quiz website. A user would start with 0 points, but end up with more so the need to continuously update/reassign values is essential.

Question 7

Give two points about const

Answer 7

1. Const must be assigned a value when declared

2. Const variable cannot be reassigned

Question 8

what does typeOf do?

Answer 8

Checks the data type of a variable’s value