Dictionaries

Question 1

What type of data type is a dictionary?

Answer 1

Abstract data type

Question 2

Define dictionary

Answer 2

An unordered collection of data as a set of key-value pairs

Question 3

What data type is a key?

Answer 3

Any simple data type

Question 4

Name 4 standard dictionary operations

Answer 4

retrieve a value associated with a particular key
insert a new key-value pair into the collection
remove a key-value pair from the collection
update a value associated with a key

Question 5

Advantages of using a key

Answer 5

Allows direct access to items stored within the collection

Provides faster access to unordered data

Question 6

How are dictionaries usually implemented?

Answer 6

Using hash tables

Question 7

Are dictionaries unordered or ordered and why?

Answer 7

Unordered because data is arranged to optimise the speed of retrieving by key

Question 8

How is a key used?

Answer 8

The same way as an index for an array is

Question 9

What do you need to insert a new value?

Answer 9

A unique key and the data