What is the point of using Initialization in structs?

Swift Programming: The Big Nerd Ranch Guide (2nd E 17. Initialization
1

I wonder if someone can explain it to me. For example, on the page 188, there is init code that adds a member wise initializer. I completely omitted the code and just wrote var myTown = Town (Region: "East", population: 10000, Stoplights: 12 ) in the main.swift and no errors popped up. Can someone explain why exactly do I need to use that init code? Thanks

2

A struct comes with a default memberwise initialiser. Therefore, provide an initialiser only when the default initialiser won’t do the job.

// With default initialiser
struct FooBar {
   let jibber: Bool
   let jabber: Int
}

// With explicit initialiser
struct FooBar2 {
   let jibber: Bool
   let jabber: Int

   init (jibber:Bool, jabber:Int) {
      self.jibber = jibber
      self.jabber = 17 * jabber
   }
}

let fooBar  = FooBar (jibber:true, jabber:9)
let fooBar2 = FooBar2 (jibber:true, jabber:9)

print (fooBar)
print (fooBar2)

For more information, read Default Initializers in The Swift Programming Language (Swift 3.0.1).