Generic term: Placeholder type placeholder

Here's a generic version of the same code:

1. struct stack<element> {
2. var items = [element] ()
3. mutating func push (_ Span class= "NV" >item: element) {
4. items. append (item)
5. }
6. mutating func pop () element {
7. return items.
8. }
9. }

Note how the generic version Stack of was essentially the same as the nongeneric version, but with a type parameter called Elementinstead of an actual type of Int . This type parameter are written within a pair of angle brackets ( <Element> ) immediately after the structure ' s name.

ElementDefines a placeholder name for a type to is provided later. This future type can is referred to as Element anywhere within the structure ' s definition. In the used as Element a placeholder in three places:

• To create a property called items , which was initialized with an empty array of values of typeElement
• push(_:)to specify that the method have a single parameter called item , which must is of typeElement
• To specify this value returned by the method would be pop() a value of typeElement

Https://docs.swift.org/swift-book/LanguageGuide/Generics.html

Generic Programming is a style of computer programming in which algorithms be written in terms of types To-b E-specified-later that is then instantiated if needed for specific types provided as parameters.

Template<T>List/* Class Contents */};  List<Animallist_of_animals;  List<Carlist_of_cars;             

Above, is T a placeholder for whatever type was specified when the list is created.

Https://en.wikipedia.org/wiki/Generic_programming

Generic term: Placeholder type placeholder