Swift Language Essentials-Dictionary (dictionary)

A dictionary stores data in the form of a key-value pair.

The key cannot be duplicated, but the value can be repeated.

Basic syntax Use cases:

var states:dictionary<string, string> = ["CA""California" = [ "CA""California"] 

You can also use type inference in the following ways:

var states = ["CA":"California"]var states= ["CA":"California","NV":"Nevada","OR":"Oregon","AZ":"Arizona"]

To modify a key value:

states["NV""Nevada"

Or

States.updatevalue ("State ofNevada""NV")

Access key value:

Let value = states["NV"]

To delete a key value:

states["TX"] = nil//  or states.removevalueforkey ( " TX ")

To traverse a key-value pair:

//iterate keys and values for(Key, value)inchStates {print ("state name = \ (value), abbreviation = \ (key)")}//Iterate Keys forAbbreviationinchStates.keys {print ("abbreviation = \ (abbreviation)")}//Iterate Values forNameinchstates.values {print ("name = \ (name)")}

Swift Language Essentials-Dictionary (dictionary)