1. .NET and .NET Core
9. Towards Higher Order
Pan Wuming
2017

2. Topics Towards Higher Order: Expressiveness
Towards Higher Order: Enhanced Dynamics
Towards Higher Order: Compiling As Services
Covariance and Contravariance
Three new languages: C#, IL and F#
Evolving from OO Paradigm
Everything is object
Members for Abstraction
Accessibility for Encapsulation
Inheritance and Polymorphism
Solving name confliction and multi-inheritance
Towards higher order: Expressiveness
Delegate
Lambda Expression
Generic
Attribute
LINQ
Compiler API
Effective coding
References：
Common Type System（MSDN）
.NET Framework Class Library Overview （MSDN）
Inheritance (C# Programming Guide) （MSDN）
Polymorphism (C# Programming Guide) （MSDN）

3. 3. Towards higher order: Expressiveness
Iterators
Lambda Expression
Generic
LINQ
Extension method
Effective Coding

4. Iterators
An iterator method or get accessor performs a custom iteration over a collection.
An iterator method uses the yield return (C#) statement to return each element one at a time.
When a yield return statement is reached, the current location in code is remembered.
Execution is restarted from that location the next time the iterator function is called.

7. Lambda Expression

8. Effective coding: Examples
Indexers
Foreach loop
Partial Class
Nullable Type
Automatic implementation of Property
Array Initialization
Implicitly Typed
Named and Optional Arguments
Int? i=5;
Instances of the System.Nullable<T> struct
public string FirstName { get; set; } = "Jane";
int[] Numbers = { 0, 1, 2, 3, 4 };
var i = 1;
var hw = "Hello World!";

9. 5. Towards Higher Order: Enhanced Dynamics
Type Class and Reflection
Dynamic Language Runtime
Dynamic languages can identify the type of an object at run time
The ability to use a rapid feedback loop (REPL, or read-evaluate-print loop).
Support for both top-down development and more traditional bottom-up development
Easier refactoring and code modifications
Dynamic languages make excellent scripting languages

10. Towards Higher Order: Compiling As Services
Compiler API
Scripting

12. See you next class
Layperson
Professional