properties.swift

// stored property, no default value
let foo: String

// stored property, default value
let foo: String = "foo"
// or
let foo = "foo"

// computed property, no custom setter
var foo: String {
    // access to other instance properties in here
    return "foo"
}

// computer property, custom setter and getter
var foo: String {
    get { return "foo" }
    set { /* do some stuff with `newValue` */ }
}

// stored property, default value provided by an immediately executed closure
let foo: String = {
    // no access to instance properties in here
    return "foo"
}()


struct Foo {
    static let foo: String = Foo.baz() // this works
    let bar: String = quz() // this doesn't, expects to be passed an instance
    
    static func baz() -> String {
        return ""
    }
    
    func quz() -> String {
        return ""
    }
}