Type Alias

     In Swift, a type alias is a way to create a new name for an existing type. This can be useful for making code more readable and expressive, or for simplifying complex type signatures. 

To create a type alias in Swift, you can use the "typealias" keyword followed by the new name and the existing type:

typealias MyInt = Int

In this example, we are creating a new type alias called "MyInt" for the existing "Int" type. We can now use "MyInt" wherever we would normally use "Int":

let myNumber: MyInt = 42
print (myNumber) // Output: 42

Type aliases can also be used for more complex types, such as tuples or function types:

typealias Person = (name: String, age: Int)

typealias Calculation = (Int, Int) -> Int

In this example, we are creating a type alias called "Person" for a tuple containing a name and an age. We are also creating a type alias called "Calculation" for a function that takes two integers and returns an integer. 

    Type aliases can make your code more readable and easier to understand, especially when working with complex types or long-type signatures. They can also make it easier to refactor your code later on if you need to change the underlying type.