Javascript Dev 1 Cert

Question 1

What are 3 ways to create Objects?

Answer 1

1. Object literal
2. Object constructor
3. Object.create()

Question 2

What way is this Object being instantiated?

var x = {}
var detail = {
                name: "nikhil"
}

Answer 2

Object literal

Question 3

What way is this Object being instantiated?

var x = new Object()
x.name = "nikhil"
console.log(x)

Answer 3

Object constructor

Question 4

What way is this Object being instantiated?

var obj = {
          name: "nikhil"
			 }
var newObj = Object.create(obj)

Answer 4

Object.create() method

Question 5

What is the output?

typeof 23.783

Answer 5

Number

Question 6

What is the output?

typeof NaN

Answer 6

Number

Question 7

What is the output?

typeof 0

Answer 7

Number

Question 8

What is the output?

typeof 0

Answer 8

Number

Question 9

What is the output?

typeof "true"

Answer 9

String

Question 10

What is the output?

var x
typeof x

Answer 10

undefined

Question 11

What is the output?

typeof null

Answer 11

object

Question 12

What is the output?

typeof {}

Answer 12

object

Question 13

What is the output?

typeof !!(1)

Answer 13

Boolean

Question 14

What is the output?

typeof function () { }

Answer 14

function

Question 15

What is the output?

typeof new Date()

Answer 15

Object

Question 16

What is the output?

String(23)

Answer 16

‘23’

Question 17

What is the output?

String(undefined)

Answer 17

‘undefined’

Question 18

What is the output?

String(null)

Answer 18

‘null’

Question 19

What is the output?

String("23")

Answer 19

‘23’

Question 20

What is the output?

String(true)

Answer 20

‘true’

Question 21

What is the output?

Number(null)

Answer 21

0

Question 22

What is the output?

Number(undefined)

Answer 22

NaN

Question 23

What is the output?

Number('hello')

Answer 23

NaN

Question 24

What is the output?

Number([])

Answer 24

0

Question 25

# What is the output? ``` Number([33, 33]) ```

Answer 25

NaN

Question 26

# What is the output? ``` Number(['523']) ```

Answer 26

523

Question 27

# What is the output? ``` Number([63.45]) ```

Answer 27

63.45

Question 28

# What is the output? ``` Boolean('') ```

Answer 28

false

Question 29

# What is the output? ``` Boolean(' ') ```

Answer 29

true

Question 30

# What is the output? ``` Boolean(undefined) ```

Answer 30

false

Question 31

# What is the output? ``` Boolean(null) ```

Answer 31

false

Question 32

# What is the output? ``` Boolean(NaN) ```

Answer 32

false

Question 33

# What is the output? ``` 100 == "100" ```

Answer 33

true

Question 34

# What is the output? ``` 100 === "100" ```

Answer 34

false

Question 35

# What is the output? ``` true == 1 ```

Answer 35

true

Question 36

# What is the output? ``` true === 1 ```

Answer 36

false

Question 37

# What is the output? ``` NaN === NaN ```

Answer 37

false

Question 38

# What is the output? ``` - 0 == 0 ```

Answer 38

true

Question 39

# What is the output? ``` NaN == NaN ```

Answer 39

false

Question 40

# What is the output? ``` - 0 === 0 ```

Answer 40

true

Question 41

# What is the output? ``` [] === [] ```

Answer 41

false

Question 42

# What is the output? ``` [] == [] ```

Answer 42

false

Question 43

# What is the output? ``` Object.is(100, "100") ```

Answer 43

false

Question 44

# What is the output? ``` var x = 10 console.log(x++) ```

Answer 44

10

Question 45

# What is the output? ``` var x = 10 x++ console.log(x); ```

Answer 45

11

Question 46

# What is the output? ``` var x = [] var y = x x === y ```

Answer 46

true

Question 47

# What is the output? ``` "Hello" + "World" + "16546542" ```

Answer 47

'HelloWorld16546542'

Question 48

# What is the output? ``` 100 + "world" ```

Answer 48

'100world'

Question 49

# What is the output? ``` 100 + null + 20 + "world" ```

Answer 49

'120world'

Question 50

# What is the output? ``` true + 1 + "hey" ```

Answer 50

'2hey'

Question 51

# What is the output? ``` undefined + 2 ```

Answer 51

NaN

Question 52

# What is the output? ``` 100 + 200 + undefined + "hey" ```

Answer 52

NaNhey

Question 53

# What is the output? ``` undefined + 2 ```

Answer 53

NaN