Revising C#. Yea I'm revising my C# basics. In this post we would discuss on
- Interfaces
- Generics
- LINQ
- Threading in C#
Value Type Vs Reference Type
- Value Types - Stored in stack (int, float, double, decimal..)
- Reference Type - Data Stored in Heap, Reference stored in Stack (Class, Interface, array, delegate)
Why Interfaces ?
- Define methods but not implement them (Reference Type)
- Cannot have Members
- Can Inherit Interfaces
Abstract Classes
- Can contain regular, abstract and non abstract members
- Cannot create instances of abstract classes
- Abstract class can be derived from other abstract classes
When to use an Abstract Class and an Interface
- Use an abstract class to provide default behavior
- Abstract Class - creating a class library which will be widely distributed or reused
- Use an interface to design a polymorphic hierarchy for value types
Example
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
//Interface Example
interface IExample
{
//Method Defined, Not Implemented
int TestInterfaceMethod(int a, int b);
}
class MyTest : IExample
{
public int TestInterfaceMethod(int a, int b)
{
return (a + b);
}
}
abstract class abstractClassExample
{
//Has both abstract and non abstract methods
public void BaseMethod()
{
Console.WriteLine("I am Base Class");
}
abstract public void AbstractBaseMethod();
}
class ChildClass : abstractClassExample
{
//Implement abstract method
override public void AbstractBaseMethod()
{
Console.WriteLine("Child Class OverWritten");
}
}
class Program
{
static void Main()
{
MyTest M = new MyTest();
Console.WriteLine(M.TestInterfaceMethod(5, 10));
ChildClass CC = new ChildClass();
CC.BaseMethod();
CC.AbstractBaseMethod();
Console.ReadKey();
}
Why Generics ?- Allow you to execute code for multiple data types
System.Collections.Generic just like:
List<T>
Dictionary<K, V>
Queue<T>
Stack<T>
How do C# generics compare to C++ templates?
Why LINQ ?
- Language Integrated Query
- Query on data collection similar to sql query to databases
Why I should use Linq?
When should we use LINQ?
LINQ: Introducing The Skip Last Operators
SQL Bits Session - LINQ for DBAs and SQL Developers
LINQ Notes
Threading in C#
C# - Use of Multithread (when) -
(Stack Overflow Question - Reposting it)
- You can use threads when you need different execution paths
- Allowing requests to be processed simultaneously
- Making efficient use of an otherwise blocked CPU
What is the difference between Deep Copy and Shallow Copy
- Reposting it from msdn question
- For instance, a Person object, containing references to an Address object, several Phone objects, etc.
- If you make a shallow copy of that Person object you now have two Person objects, but they share the Address objects and Phone objects. In other words, you only make a new Person object, and then link it up to the existing Address and Phone objects.
- A deep copy, on the other hand, will make new copies of everything, so that both Person objects now have their own set of Address and Phone objects.
When is a shallow copy desirable (instead of a deep copy)? (Stack Overflow Question - Reposting it)
- In C++, you might use deep copying to avoid difficult memory management issues
- In Java/.NET, deep copying is not necessary for those reasons. Since the languages are both garbage collected
Static Methods Example
Still remember c basics. They still seem to hold true. Tested below code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication1
{
class Program
{
static int i=0;
static void TestMethod()
{
//only one copy exists throught the program
//last modified value used in this case
i++;
Console.WriteLine("Value of it is " + i);
Console.ReadKey();
}
void TestforValueMethod()
{
//Local variable hides global variable
int i=0;
Console.WriteLine("Value of i is " + i);
i++;
Console.ReadKey();
}
static void Main(string[] args)
{
//static method invoking without class creation
TestMethod();
TestMethod();
TestMethod();
Console.ReadKey();
Program p = new Program();
p.TestforValueMethod();
TestMethod();
Console.ReadKey();
}
}
}
Output is
More Reads
What is the difference between Arraylist.Copy() vs Arraylist.Clone()
ADO.NET: Building a Custom Data Provider for Use with the .NET Data Access Framework
Very Good Article Series for
.NET Test Automation Series
I recommend Illustrated C# 2010 book. Awesome book.
Happy Reading!!
