Swift Language Generics Generic Class Examples
Example
A generic class with the type parameter Type
class MyGenericClass<Type>{
var value: Type
init(value: Type){
self.value = value
}
func getValue() -> Type{
return self.value
}
func setValue(value: Type){
self.value = value
}
}We can now create new objects using a type parameter
let myStringGeneric = MyGenericClass<String>(value: "My String Value")
let myIntGeneric = MyGenericClass<Int>(value: 42)
print(myStringGeneric.getValue()) // "My String Value"
print(myIntGeneric.getValue()) // 42
myStringGeneric.setValue("Another String")
myIntGeneric.setValue(1024)
print(myStringGeneric.getValue()) // "Another String"
print(myIntGeneric.getValue()) // 1024Generics can also be created with multiple type parameters
class AnotherGenericClass<TypeOne, TypeTwo, TypeThree>{
var value1: TypeOne
var value2: TypeTwo
var value3: TypeThree
init(value1: TypeOne, value2: TypeTwo, value3: TypeThree){
self.value1 = value1
self.value2 = value2
self.value3 = value3
}
func getValueOne() -> TypeOne{return self.value1}
func getValueTwo() -> TypeTwo{return self.value2}
func getValueThree() -> TypeThree{return self.value3}
}And used in the same way
let myGeneric = AnotherGenericClass<String, Int, Double>(value1: "Value of pi", value2: 3, value3: 3.14159)
print(myGeneric.getValueOne() is String) // true
print(myGeneric.getValueTwo() is Int) // true
print(myGeneric.getValueThree() is Double) // true
print(myGeneric.getValueTwo() is String) // false
print(myGeneric.getValueOne()) // "Value of pi"
print(myGeneric.getValueTwo()) // 3
print(myGeneric.getValueThree()) // 3.14159
