Week 1

Question 1

Name 3 variable keywords.

Answer 1

var
let
const

Question 2

What is a variable?

Answer 2

A variable is a named container used for storing data or values.

Question 3

Write an example of a variable.

Answer 3

let fruit = ‘apple’;

Question 4

Is var hello = ‘hello’; the same as var Hello = ‘hello’; ?

Answer 4

Nope! Variable naming is case sensitive.

var hello is a different variable than var Hello.

Question 5

When do we use the keyword ‘const’?

Answer 5

We use the keyword ‘const’ to create a variable of which we don’t want the value to be able to be changed or altered at any given time.

Question 6

Deconstruct the following variable example: 
let b = 1;

What are the names of the 4 components that create a variable?

Answer 6

1 - Keyword
2 - Variable Name
3 - Assignment Operator
4 - Variable Value

Question 7

What does the left hand side of a variable refer to?

let x ;

Answer 7

The left hand side of a variable is called the ‘declaration’. It is simply the variable keyword and the variable name.

Question 8

What does the right hand side of a variable refer to?

x = 10 ;

Answer 8

The right hand side of a variable is called the ‘initialization’. It includes the variable name, assignment operator, and the value of the variable.

Question 9

Name the 6 basic data types in JavaScript we covered in class and write an example for each of them.

Answer 9

1. Boolean: let boolean = true;
2. Number: let num = 14;
3. String: let string = ‘Hello’;
4. Null: let nothing = null;
5. Undefined: let undef = undefined;
6. Object: let food = [‘pizza’, ‘shrimp’];

Question 10

What does JavaScript use to join strings?

Answer 10

In JavaScript, we can use concatenation to join strings together to build sentences.

Question 11

Which method uppercases all the letters in a string?

Answer 11

Methods are tools that allow us to manipulate data.

myName.toUpperCase( ) ;

Question 12

How do you make a directory through the command line?

Answer 12

mkdir

Question 13

How do you check what folders you can access in the command line?

Answer 13

ls (for mac)

dir (for pc)

Question 14

How do you change directories in the command line?

Answer 14

cd

Question 15

How do you back up one directory in the command line?

Answer 15

cd ..

Question 16

What data type is this an example of?
let example = 'Hello';

Answer 16

String

Question 17

What data type is this an example of?
let example = 0;

Answer 17

Integer

Question 18

What data type is this an example of?
let example = true;

Answer 18

Boolean

Question 19

Rewrite the following as a Switch:

let test = 5;
if (typeof test === 'string') {
  console.log("It's a string!");
} else if (typeof test === 'number') {
  console.log("It's a number!");
} else if (typeof test === 'boolean') {
  console.log("It's a boolean!");
} else {
console.log("It's something else!")
}

Answer 19

switch (typeof test) {
  case 'string':
    console.log("It's a string!");
    break;
  case 'number':
    console.log("It's a number!");
    break;
case 'boolean':
    console.log("It's a boolean!");
    break;
  default:
    console.log("It's something else!");
    break;
}

Question 20

What will the following console log?

let test = '3';
if (test === 3){
  console.log('Yep!')
} else {
  console.log('Nope!')
}

Answer 20

Nope!

Question 21

What will the following console log?

let test = 3;
if (test === 3){
  console.log('Yep!')
} else {
  console.log('Nope!')
}

Answer 21

Yep!

Question 22

What will the following console log?

let test = '3';
if (test == 3){
  console.log('Yep!')
} else {
  console.log('Nope!')
}

Answer 22

Yep!

Question 23

Subtraction assignment operator

Answer 23

x -= 1

Question 24

Addition assignment operator

Answer 24

x += 1

Question 25

Multiplication assignment operator

Answer 25

x *= 1

Question 26

Division assignment operator

Answer 26

x /= 1

Question 27

Remainder (or modulus) operator

Answer 27

x %= 1

Question 28

Exponential assignment operator

Answer 28

x **= 1

Question 29

Equal comparison operator

Answer 29

==

Question 30

Strict equal comparison operator

Answer 30

===

Question 31

Not equal comparison operator

Answer 31

!=

Question 32

Strict not equal comparison operator

Answer 32

!==

Question 33

And comparison operator

Answer 33

&&

Question 34

Or comparison operator

Answer 34

||

Question 35

Write a ternary that console logs “It worked!” if a number is between 1 and 10 and console logs “It didn’t work” if it is not.

Answer 35

let num = 9;
(num < 11 &amp;&amp;; num > 0) ? console.log('It worked!') : console.log('It didn\'t work.')

Question 36

Write an else if statement that checks the variable weather. If it is hot console log “Wear a t-shirt”, if it is cold console log “wear a coat” and if it is rainy console log “bring an umbrella”

Answer 36

let weather = 'cold';
if (weather === 'rainy'){
  console.log('Bring an umbrella')
} else if (weather === 'hot') {
  console.log('Wear a t-shirt')
} else if (weather === 'cold') {
  console.log('Wear a coat')
}