Dictionaries

- Before the days of the internet,…when you wanted to look up the meaning of a word,…you could look it up in a dictionary like this one.…This dictionary holds thousands of definitions in it,…and I can find the definition I'm looking for…very quickly, because I can index it…using the associated word.…In the programming world,…dictionary is a term that's used to describe…a data structure that stores a collection…of key and value pairs.…You might also hear words like map, simple table,…or hash table,…which also accomplish the same thing.…Just like with a real life dictionary,…I can look up values quickly…by using the associated keys.…

Fortunately, programming dictionaries…aren't limited to just storing words and definitions.…Time to invite my friends over.…Now, some people might call me old fashioned,…but I like to keep track of my friends' phone numbers,…in my trusty old, pen and paper Rolodex.…My Rolodex is just like a dictionary.…Each card in my Rolodex contains a single name…and the corresponding number for that person.…