Can ANYONE give me a GOOD English explanation not too complicated on of initializers ! Thanks :D

I can give a simple definition because I am new to programming and I teach English in Japan HaHa.

Swift enforces you to initialize every property before it is ever/might ever be used. It’s a safety feature in Swift related to something else in programming called superInit but don’t worry about that.

An initializer is a block of code that is created immediately after objects such as structs, enums or classes.

The main purpose of an initializer is to initialize the properties that have not been initialize yet.

All the properties/attributes have to be initialized or else you will get an error. Again, you cannot construct an object without all of its properties initialized.

Initializers are like special functions/methods that can be used to create a new instance of a particular type. Swift initializers do not return a value. Their primary role is to ensure that new instances of a type are correctly initialized before they are used for the first time. In the example code below “Vehicle” is a type.

An initializer method extends the functionality of objects. If you didn’t want to select a specific member value when creating an instance then you can provide an init method which defaults to one of the member values.

You don’t have to initialize a property in the init method. You can also initialize a property right after the property as shown in the code example below.

Optionals like “String?” are initialized the moment they are declared therefore you don’t need to initialize them inside the initializer.

In the code example below ’name’ is a constant “let name:String”, but actually it can be changed as shown in the code example. This programming feature can only be done in an initializer.

Class Vehicle {

    var currentSpeed:Int // you could initialize like this “var currentSpeed:Int = 2”
    let name:String
    var description:String
    var color:String?   // Optionals don’t need to be initialized

    init() {
      currentSpeed = 1  // Good to put in a default value in this game
      name = “unknown”  // Constants can only be modified here
      description = “\(name) running at speed of \(currentSpeed)”
    }
}

This Apple documentation is simple and excellent. https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Initialization.html