What symbol is prefixed before the name of an attribute?

Which of the following is not a valid access level in Swift?

Which keyword is not needed when implementing a required initializer in Swift?

Where should a programmer define the access type of a custom type in Swift?

What is the purpose of the self keyword?

What are the two different types of initializers that Swift provides for classes?

What happens if a programmer delegates from init to init!?

What types should we use in Swift classes if we want a property to store a nil value at some point in the program?

What will be the output of the following code?

var variableString = "Horse";

variableString += " and carriage";

console.log(variableString);

What will happen when we run the following code?

let name: String! = nil

let sound: String = name