All

Question 1

what is an operator

Answer 1

+, -, =, <

Question 2

what are the 7 data types

Answer 2

numbers, strings, boolean, symbols, objects, null, undefined

Question 3

what does Typeof do

Answer 3

operator that tells the data type

Question 4

Numbers

Answer 4

1, 3, .87, -4

Question 5

strings

Answer 5

letters. represent text using ‘’

Question 6

Booleans

Answer 6

true or false

Question 7

objects

Answer 7

collection of data

Question 8

what does objects include

Answer 8

key and values in {} brackets

Question 9

Arrays

Answer 9

list of values in square brackets []

Question 10

Null

Answer 10

intentionally absent object or not a possible value

Question 11

undefined

Answer 11

not yet assigned a value

Question 12

interpolation

Answer 12

back ticked ` ` can be used for string

Question 13

interpolation operations

Answer 13

${ insert value}

Question 14

how can you combine strings

Answer 14

string + string

Question 15

boolean expression

Answer 15

expressions that return true or false (1 > 0)

Question 16

what data types are falsey

Answer 16

false, null, undefined, 0, NaN, empty string “ “

Question 17

what are strict equality operator

Answer 17

===

Question 18

what are strict inequality operator

Answer 18

! ==

Question 19

what is not operator

Answer 19

!

Question 20

what is and operator

Answer 20

&&

Question 21

what is or operator

Answer 21

||

Question 22

tenary expression syntax

Answer 22

true or false value ? return if true : return if false

Question 23

if statement syntax

Answer 23

if (condition) {
code to run if condition is true}

Question 24

else statement syntax

Answer 24

if (condition) {
code to run if condition is true} else {
code to run if condition is false}

Question 25

if else statement syntax

Answer 25

if (condition) { code to run if condition is true} else if (other condition){ code to run if other condition is true}

Question 26

switch statement syntax

Answer 26

switch(expression) { case x: // code block break; case y: // code block break; default: // code block }

Question 27

while loop syntax

Answer 27

while (condition) { code to run while condition is true; counter to end loop; }

Question 28

symbol to increase 1

Answer 28

++

Question 29

symbol to decrease 1

Answer 29

--

Question 30

function syntax

Answer 30

function nameFunction (parameter) { function body }

Question 31

parameters

Answer 31

names listed in function definition. not actually run but a placeholder

Question 32

argument

Answer 32

the values passed into function.

Question 33

return definition

Answer 33

statement that ends function execution and specifies a value to be returned to the function caller

Question 34

what does parseInt() do

Answer 34

turns numbers inside strings from string to numbers. parseInt("2") becomes 2

Question 35

what are data in arrays identified with

Answer 35

Index

Question 36

.length does what in an Array

Answer 36

finds the number of elements in the array

Question 37

what is the index of the first number in an array

Answer 37

0

Question 38

how do you rename an element in an array

Answer 38

array[index to change]= "new element"

Question 39

how do you reach a nested array for 3 [1,2 ,[3]]

Answer 39

[0][0]

Question 40

.push ()

Answer 40

add to end of array destructively

Question 41

.unshift ()

Answer 41

add to beginning of an array destructively

Question 42

how to add non destructively

Answer 42

spread operator

Question 43

what is spread operator symbol

Answer 43

...

Question 44

example of using spread operator to add to end of array

Answer 44

newArray= [...array, "element to add"]

Question 45

example of using spread operator to add to beginning of array

Answer 45

newArray = ["element to add", ... array]

Question 46

.pop()

Answer 46

removes last element of array destructively

Question 47

.shift()

Answer 47

removes first element of array destructively

Question 48

how to remove elements non destructively

Answer 48

.slice()

Question 49

using .slice ()

Answer 49

const newArray= array.slice(start index, stop index)

Question 50

how to get last element of array

Answer 50

-1

Question 51

what can .splice do

Answer 51

add, remove or replace

Question 52

.splice syntax

Answer 52

array.splice(start index, end index, "new element")

Question 53

object syntax

Answer 53

const obj = { key 1 : value 1, key 2: { innerkey 1: innervalue 1, } }

Question 54

dot notation

Answer 54

way to access value stored in object

Question 55

dot notation syntax

Answer 55

object. key

Question 56

bracket notation

Answer 56

uses brackets [ ] to access objects

Question 57

bracket syntax for objects

Answer 57

object ["key"]

Question 58

object.keys ()

Answer 58

pulls all of the key at the top level in a object

Question 59

object.values()

Answer 59

returns all of the object values not the keys

Question 60

adding properties to objects with dot notation

Answer 60

object.key = new value

Question 61

adding properties to objects with brackets

Answer 61

object["key"] = value

Question 62

how to remove an element in array

Answer 62

delete object.key

Question 63

nondestructive add to object

Answer 63

use spread operator (...) const newobject = {... object} newobject["Key"] = value

Question 64

for loop syntax

Answer 64

for ( initialization; condition; iteration) { code that runs for each pass }

Question 65

for loop initialization

Answer 65

counter variable. example= let age = 20

Question 66

for loop condition

Answer 66

expression to evaluate before each loop pass. example: age < 40

Question 67

for loop iteration

Answer 67

what happens at the end of the loop. example: age ++

Question 68

what is looping

Answer 68

process of executing a set of statements repeatedly until a condition is met

Question 69

what is iteration

Answer 69

process of executing a set of statements once for each element in a collection

Question 70

what is used for iteration in arrays

Answer 70

for ... of

Question 71

for... of syntax

Answer 71

const array1 = ['a', 'b', 'c']; for (const element of array1) { console.log(element); }

Question 72

iterating over strings

Answer 72

for... of

Question 73

iterating over objects

Answer 73

for ... in

Question 74

for ... in syntax to return key

Answer 74

for (const [key] in [object]) { console.log(key); }

Question 75

for ... in syntax to return key

Answer 75

for (const [key] in [object]) { console.log(object['key']); }

Question 76

what makes a copy of an object

Answer 76

object assign({}, object)

Question 77

.map

Answer 77

loops through array and return a new array without changing the original array

Question 78

.map syntax

Answer 78

const newFunctionName = object.map(function(item)){ return item.key }