Dictionary in Swift

Where? How does the Swift compiler store values in a Dictionary?

Photo by Dmitry Ratushny on Unsplash

These are called HashMaps in Java, but whatever language you are coming from a dictionary is a data structure that maps keys to values.

Prerequisites:

• Be able to produce a “Hello, World!” iOS application (guide HERE)
• Knowledge of optionals (guide HERE)
• Be familiar with += to increment values (guide HERE)
• Knowing something about force unwrapping would be useful (guide HERE)
• Knowing about Mutability is important (guide HERE)

Terminology

Character: A written character, usually associated with a letter of the alphabet

Dictionary: The association between keys and values (where all the keys are of the same type, and all values are of the same type)

Increment: An operator (+=) that adds one to the operand

Integer: A number that has no fractional part, that is no digits after the decimal point

Key-value pairs: A set of two linked data items, a unique identifier (key) and an item of data (value)