added example for open close principle

Author: Sebastian Boldt

GOFSwift.xcworkspace/xcuserdata/sboldt.xcuserdatad/UserInterfaceState.xcuserstate

@@ -1,4 +1,4 @@
-# GoF & S.O.L.I.D in Swift
+# GoF & SOLID in Swift
 👨‍👩‍👧‍👦 My personal Repo to learn all GOF und SOLID Patterns using Swift and Playgrounds
 
 ✅ Implemented and internalized
@@ -59,13 +59,13 @@
 
 ✅ Virtual Proxy
 
-## S.O.L.I.D
+## SOLID
 
 ✅ Dependency Inversion Principle (DIP)
 
 ✅ Single Responsibilty Principle  (SRP)
 
-❌ Open Closed Principle (OCP)
+✅ Open Closed Principle (OCP)
 
 ❌ Liskov Substitution Principle (LSP)
 

README.md

@@ -4,4 +4,35 @@ import Foundation
 
 // SOFTWARE ENTITIES (CLASSES, MODULES, FUNCTIONS, ETC.) SHOULD BE OPEN FOR EXTENSION, BUT CLOSED FOR MODIFICATION.
 
+protocol Printable {
+    func printElement()
+}
+
+public struct Printer {
+    func print(printables: [Printable]) {
+        for printable in printables {
+            printable.printElement()
+        }
+    }
+}
+
+struct Student: Printable {
+    var name: String
+    
+    func printElement() {
+        print("student \(name)")
+    }
+}
+
+struct Teacher: Printable {
+    var name: String
+    func printElement() {
+        print("teacher: \(name)")
+    }
+}
+
+
+let printables: [Printable] = [Student(name: "Peter"), Teacher(name: "James")]
+Printer().print(printables: printables)
+
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