Classes are the heart of any object-oriented programming language. Unlike classes in Objective-C and some other languages, Swift’s classes need no header declaration. Instead, you get the entire class (or structure or enumeration) definition in a format like this:
class MyClass {
var storedNumber: Int = 0
init (myNumber storedNumber: Int) {
self.storedNumber = storedNumber
}
func simpleDescription() -> String {
return String(self.storedNumber)
}
}
var test = MyClass(myNumber: 15)
println ("myNumber is " + test.simpleDescription());
The code in this example defines a class. Note the following characteristics:
It declares a stored property. It is an Int set initially to 0.
It creates an initializer that takes an Int as a parameter. The external name is myNumber and the internal name is storedNumber. The initializer sets the class instance value self.storedNumber using the storedNumber parameter (with the external name myNumber).
It declares a function called simpleDescription that returns a String representation of the stored number.
