How exactly does the “let” keyword work in Swift?

Question

I\'ve read this simple explanation in the guide:

The value of a constant doesn’t need to be known at compile time, but you must assign it a value exa

Answer 1

F# users will feel right at home with Swift's let keyword. :)

In C# terms, you can think of "let" as "readonly var", if that construct was allowed, i.e.: an identifier that can only be bound at the point of declaration.