From f8ff01a17eff289e6e5e84a129dd29fa9a8bcdff Mon Sep 17 00:00:00 2001
From: Wayne Boka <boka.wayne@gmail.com>
Date: Wed, 3 Oct 2018 16:23:54 -0400
Subject: Add Readonly Examples

In references to #2702. Making another commit due to several extra files getting committed.
---
 typescript.html.markdown | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'typescript.html.markdown')

diff --git a/typescript.html.markdown b/typescript.html.markdown
index acc258b4..db6579e2 100644
--- a/typescript.html.markdown
+++ b/typescript.html.markdown
@@ -178,6 +178,37 @@ let greeting = `Hi ${name}, how are you?`
 let multiline = `This is an example
 of a multiline string`;
 
+// READONLY: New Feature in TypeScript 3.1
+interface Person {
+  readonly name: string;
+  readonly age: number;
+}
+
+var p1: Person = { name: "Tyrone", age: 42 };
+p1.age = 25; // Error, p1.x is read-only
+
+var p2 = { name: "John", age: 60 };
+var p3: Person = p2; // Ok, read-only alias for p2
+p3.x = 35; // Error, p3.x is read-only
+p2.x = 45; // Ok, but also changes p3.x because of aliasing
+
+class Car {
+  readonly make: string;
+  readonly model: string;
+  readonly year = 2018;
+
+  constructor() {
+    this.make = "Unknown Make"; // Assignment permitted in constructor
+    this.model = "Unknown Model"; // Assignment permitted in constructor
+  }
+}
+
+let numbers: Array<number> = [0, 1, 2, 3, 4];
+let moreNumbers: ReadonlyArray<number> = numbers;
+moreNumbers[5] = 5; // Error, elements are read-only
+moreNumbers.push(5); // Error, no push method (because it mutates array)
+moreNumbers.length = 3; // Error, length is read-only
+numbers = moreNumbers; // Error, mutating methods are missing
 ```
 
 ## Further Reading
-- 
cgit v1.2.3


From 67730b4e0b3100a7a6df925ef28606b71aa30a43 Mon Sep 17 00:00:00 2001
From: Bradley Kemp <bradleyjkemp@users.noreply.github.com>
Date: Fri, 19 Oct 2018 13:55:51 +0100
Subject: Add example of "implements" keyword

---
 typescript.html.markdown | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'typescript.html.markdown')

diff --git a/typescript.html.markdown b/typescript.html.markdown
index db6579e2..9158f123 100644
--- a/typescript.html.markdown
+++ b/typescript.html.markdown
@@ -113,6 +113,13 @@ class Point {
   static origin = new Point(0, 0);
 }
 
+// Classes can be explicitly marked as implementing an interface.
+// Any missing properties will then cause an error at compile-time. 
+class PointPerson implements Person {
+    name: string
+    move() {}
+}
+
 let p1 = new Point(10, 20);
 let p2 = new Point(25); //y will be 0
 
-- 
cgit v1.2.3