# Computing - Hash Tables

What is the main advantage of a hash table?

You can quickly find items given a key.

A hash table is a type of what data type?

An Abstract Data Type.

How is an element’s key calculated?

Using a hash function.

A key-value hash table is sometimes called what?

A hash map.

What is a hashing algorithm?

A calculation applied to a key to transform it into an address.

What is it called when a hash function generates the same value for two different inputs?

A collision.

What is it called when you find a new place for a value after two inputs have the same hash?

Open addressing.

What is the formula for load factor?

What can load factor be used for?

Calculating when it is neccassary to allocate more space to store something.

Once a hash has been calculated, what operation is used to normalise it to the length of the array?

What is a common method of calculating a hash for a string?

Adding together the ASCII numbers of the characters.