How is optional binding used in swift?

Question

In swift the following syntax is allowed for flow control

if let constantName = someOptional {
    statements
}

In this context wh

Answer 1

Think of it like this: An optional is just an Enum with an associated value.

enum OptionalValue {
    case None
    case Some(T)
}

When you assign to an optional, under the hood the .Some enum value is used, with an associated value that you gave. If you assign it to nil, it's given the value None, with no associated value.

if let constantName = someOptional {}

Does the if on the enum. If it's .Some, then the constant is assigned the associated value, and the block is executed. Otherwise nothing happens.