@property/@synthesize equivalent in swift
ios, ios8, objective-c, swift
Solution
Swift provides no differentiation between properties and instance variables (i.e, the underlying store for a property). To define a property, you simply declare a variable in the context of a class.
A swift class is simply a ClassName.swift file.
You declare a class and properties as
class SomeClass {
var topSpeed: Double
var aStrProperty: String
var anIntProperty: Int
//Initializers and other functions
}
You access property values via dot notation. As of Xcode6 beta 4, there also are access modifiers (`public`, `internal` and `private`) in Swift. By default every property is `internal`. See here for more information.
For more information, refer to the Swift Programming Guide:
Stored Properties and Instance Variables
If you have experience with Objective-C, you may know that it provides two ways to store values and references as part of a class instance. In addition to properties, you can use instance variables as a backing store for the values stored in a property.
Swift unifies these concepts into a single property declaration. A Swift property does not have a corresponding instance variable, and the backing store for a property is not accessed directly. This approach avoids confusion about how the value is accessed in different contexts and simplifies the property’s declaration into a single, definitive statement. All information about the property—including its name, type, and memory management characteristics—is defined in a single location as part of the type’s definition.
Problem
We used to declare `property` to pass data between classes as following: ``` .h file (interface file) @property (nonatomic) double topSpeed; .m file (implementation file) @synthesize topSpeed; ``` Now there is no `interface` class, how to pass data between `.swift` classes ?