Map

Question 1

Map is similar to what DS?

Answer 1

Object. Both operate w/ key value pairs.

Question 2

Key types

Answer 2

Any value (array, Objs, or any primitive)

Question 3

Key order

Answer 3

A Map iterates in the order of insertion

Question 4

Is a Map iterable?

Answer 4

Yes. Can be directly iterated.

Question 5

Which performs better, Object or Map?

Answer 5

Map when frequently adding & removing kv pairs.

Question 6

How to return the number of elements?

Answer 6

Map.size

Question 7

Map.clear()

Answer 7

Does- removes all elements from Map object

Params- none

Returns- undefined

Question 8

Map.delete()

Answer 8

Does- removes a specified element

Params- key

Returns- bool. True if object existed and was removed. False if it doesn’t exist

Question 9

Map.entries() vs Map.keys() vs Map.values()

Answer 9

Entries - returns a new Map iterator w/ key-value pairs in insertion order

Keys - returns a new Map iterator w/ all keys in insertion order

Values- returns a new Map iterator w/ all values in insertion order

Question 10

Map.get()

Answer 10

Does- returns a specified element from Map object

Params -Key

Returns - associated elements value or undefined

Question 11

Map.set()

Answer 11

Does - inserts/updates a key-value in Map object

Params - key, value

Returns Map object

Question 12

Map.has()

Answer 12

Does - tells if key exists in Map object

Params - key

Returns - bool based on if key exists