Day 2 :

arrays, sets, Tuples, dictionaries and enums

1.Swift’s strings, integers, Booleans, and Doubles allow us to temporarily store single values, but if you want to store many values you will often use arrays instead.

An array stores values of the same type in an ordered list.

var Names: [String] = ["Saurabh","Sachin"]

Array position start with 0,so if you want to read sachin then

Name[1]

1. Sets are unordered collections of unique values.

var favoriteGenres: Set<String> = ["Rock", "Classical", "Hip hop"]

or 

var favoriteGenres: Set = ["Rock", "Classical", "Hip hop"]

If you try to insert a duplicate item into a set, the duplicates get ignored.

var favoriteGenres: Set = ["Rock", "Classical", "Hip hop","Rock","Classical"]

You can create set from Array

var Names= set(["Saurabh","Sachin"])

3.Tuples are created by placing multiple items into parentheses, like this:

var name = (first: "Taylor", last: "Swift")

access item from tuple

name.0
or
name.first

Remember, you can change the values inside a tuple after you create it, but not the types of values.So, if you tried to change name to be (first: "Justin", age: 25) you would get an error.

4.A dictionary stores associations between keys of the same type and values of the same type in a collection with no defined ordering

var someDict:[Int:String] = [1:"One", 2:"Two", 3:"Three"]

5.According to the Swift documentation enumeration is defined as “a common type for a group of related values and enables you to work with those values in a type-safe way within your code”.
for more details about enum Click Here..

6.Creating empty collections
Arrays, sets, and dictionaries are called collections, because they collect values together in one place.
Empty Dictionary

var teams = [String: String]()

we can add

teams["Paul"] = "Red"

empty Array

var results = [Int]()

empty set

var words = Set<String>()
var numbers = Set<Int>()