Introduction to Javascript

Question 1

Console

Answer 1

A panel that displays important messages, like errors, for developers.

Question 2

Code Comments

Answer 2

As we write JavaScript, we can write comments (instructions or useful annotations) in our code that the computer will ignore as our program runs. These comments exist just for human readers.

Question 3

What are the two types of code comments?

Answer 3

1. Single Line comment (/)
2. Multi line comment - in front (/) at end (/)

Question 4

Data types

Answer 4

classifications we give to the different kinds of data that we use in programming.

Question 5

What are the seven fundamental data types:

Answer 5

• Number
• String
  -Boolean
  -Null
  -Undefined
  -Symbol
  -Object

Question 6

What data types are considered primitive data types

Answer 6

• Number
• String
  -Boolean
  -Null
  -Undefined
  -Symbol

Question 7

Explain a “Number” Data Type

Answer 7

Any number, including numbers with decimals: 4, 8, 1516, 23.42.

Question 8

Explain a “String” Data Type

Answer 8

Any grouping of characters on your keyboard (letters, numbers, spaces, symbols, etc.) surrounded by single quotes: ‘ … ‘ or double quotes “ … “, though we prefer single quotes. Some people like to think of string as a fancy word for text.

Question 9

Explain a “Boolean” Data Type

Answer 9

This data type only has two possible values— either true or false (without quotes). It’s helpful to think of booleans as on and off switches or as the answers to a “yes” or “no” question.

Question 10

Explain a “Null” Data Type

Answer 10

This data type represents the intentional absence of a value, and is represented by the keyword null (without quotes).

Question 11

Explain a “Undefined” Data Type

Answer 11

This data type is denoted by the keyword undefined (without quotes). It also represents the absence of a value though it has a different use than null. undefined means that a given value does not exist.

Question 12

Explain a “Symbol” Data Type

Answer 12

A newer feature to the language, symbols are unique identifiers, useful in more complex coding.

Question 13

Explain a “Object” Data Type

Answer 13

Collections of related data.

Question 14

What is an “Operator”

Answer 14

a character that performs a task in our code.

Question 15

JavaScript has several built-in arithmetic operators, that allow us to perform mathematical calculations on numbers. List the arithmetic operators and their corresponding symbols

Answer 15

Add: +
Subtract: -
Multiply: *
Divide: /
Remainder: %

Question 16

What is the “remainder” operator sometimes called

Answer 16

modulo

Question 17

Concatenation

Answer 17

appends one string to another

Question 18

Methods

Answer 18

‘Methods’ are actions we can perform. Data types have access to specific methods that allow us to handle instances of that data type.

Question 19

What are the Javascript “string methods”? This are methods that we ‘call’ or ‘use’, by appending an instance with:

Answer 19

-a period (the dot operator)
-the name of the method
-opening and closing parentheses

E.g. ‘example string’.methodName().