TypeScript 101. TypeScript is a tool that allows you to utilize object oriented programming techniques with your JavaScript code. With TypeScript you have the same sort of namespaces and classes that you use to build your business objects. TypeScript classes support both inheritance and interfaces. We’ll introduce you to these concepts and show you how to use TypeScript to manage and organize your JavaScript code.

1. TypeScript 101
Ross Terman
www.xeq.com
rterman@xeq.comt
ed by Ross Terman

2. What is TypeScript
TypeScript is a superset of JavaScript
You can enter pure JavaScript into TypeScript
TypeScript gives you type safety.
TypeScript gives you encapsulation.
TypeScript allows you to organize your code into Modules and Classes

3. Get TypeScript
www.TypeScriptLang.org
http://www.typescriptlang.org/Content/TypeScript
%20Language%20Specification.pdf
Web Essentials

4. TypeScript Features
• Standard JavaScript Code
• Static Typing
• Encapsulation with Modules and Classes
• Classes support Constructors, Properties,
Fields and Functions
• Interfaces
• Lambda Functions =>
• Intellisense and syntax checking

5. Additional Keywords and Operators
 exports and imports
constructor
extends
implements
Interface
public/private
… Rest syntax
=> Arrow or lambda functions
<typename> type conversion
: assignment

6. Code Hierarchy
Module
Interface Class
Fields
Constructors
Properties
Functions

7. Types
Type Inference
Annotations
Type Definition Files
Primitive Types: Number, String, Boolean, Any, Null, Undefined
Object Types

8. Functions
Parameters – Required and Optional
Arrow (lambda) functions
Void for functions that return no value

9. Classes
Class Members – Fields, Properties, Functions, Constructors
Add functions to a class. Note lack of function keyword
Define properties
Complex Types (object types) – Instantiate with New keyword
Types can be cast
https://github.com/borisyankov/DefinetlyTyped
Extending Types – super() function. Similar to base
Immediately-invoked function expression – iffy

10. Interfaces
Optional members
Implementing
Using an Interface as a type
Extend interface

11. Modules
Benefits – Separation of concern, maintainable, testable, reusable
Open – Can be exposed for both Import and Export
Asynchronous Module Definition - AMD

12. Resources
http://www/typescriptlang.org
http://www.typescriptlang.org/Content/TypeScript%20Language%20Specifica
tion.pdf
http://www.johnpapa.net/
http://weblogs.asp.net/dwahlin/
http://pluralsight.com/training/

13. Contact Us
Ross Terman – 305-726-6925
rterman@xeq.com
@xeqinfo