Semantic portal
Generic Classes
class Stack[A] {
private var elements: List[A] = Nil
def push(x: A) { elements = x :: elements }
def peek: A = elements.head
def pop(): A = {
val currentTop = peek
elements = elements.tail
currentTop
}
}val stack = new Stack[Int]
stack.push(1)
stack.push(2)
println(stack.pop) // prints 2
println(stack.pop) // prints 1class Fruit
class Apple extends Fruit
class Banana extends Fruit
val stack = new Stack[Fruit]
val apple = new Apple
val banana = new Banana
stack.push(apple)
stack.push(banana)Generic classes are classes which take a type as a parameter.
Generic Classes → are a → Classes.
Defining a generic class
class Stack[A] {
private var elements: List[A] = Nil
def push(x: A) { elements = x :: elements }
def peek: A = elements.head
def pop(): A = {
val currentTop = peek
elements = elements.tail
currentTop
}
}Generic classes take a type as a parameter within square brackets []. One convention is to use the letter A as type parameter identifier, though any parameter name may be used.