Hash Tables Recap

A hash table is

• an abstract data structure

• an array

• an integer

• made of pine

What is the purpose of hashing in computer science?

• To transform a string of characters into a shorter length value

• To illustrate the concept of data structures

• To distribute keys in an array using a hash function

• To store and retrieve keys in a rapid manner

Address <----- key MOD(numberOfSlots)

IF KEY = 5432 and numberOfSlots = 1000

Address = ?

• 5

• 432

• 543

• 5432

Address <----- key MOD(numberOfSlots)

IF KEY = 5432 and numberOfSlots = 100

Address = ?

• 5

• 4

• 32

• 5432

when an algorithm generates the same address for different primary keys it is known as

• Knock

• Bang

• Collisions

• DoubleHash

What is a hashing function used for?

• To calculate the position of an item in a hash table

• To determine the size of a hash table

• To compare items in a data set

• To implement a dictionary data structure

What is a collision in a hash table?

• When two data items have the same hash value

• When a hash table is too small to store all the data items

• When a hashing function takes too long to calculate

• When a hash table is empty

What are the three basic operations that can be performed on a hash table?

• Adding a value, deleting a value, retrieving a value

• Sorting a value, searching a value, updating a value

• Copying a value, moving a value, renaming a value

• Creating a value, reading a value, updating a value

What is the purpose of an overflow table in a hash table?

• To store items that cannot be placed in the hash table

• To prevent collisions in a hash table

• To speed up the hashing function

• To reduce the memory footprint

What is the purpose of a linked list in a hash table?

• To store items that cannot be placed in the hash table

• To prevent collisions in a hash table

• To speed up the hashing function

• To reduce the memory footprint