Notes for revision of .net

These are the notes i read to revise concepts:

Before DOT NET Framework COM is there. COM stands for Component Object Model. The COM is one of the Microsoft Frameworks. Using this Framework, we can develop Windows Applications

There are two major disadvantages of the COM Framework. They are as follows:

1. Incomplete Object-Oriented Programming means it will not support all the features of OOPs.

2. Platform Dependent means COM applications can run on only Windows OS.

   NET stands for Network Enabled Technology (Internet). In .NET, dot (.) refers to Object-Oriented, and NET refers to the internet. So, the complete .NET means through Object-Oriented we can implement internet-based applications.

The DOT NET Framework provides two things as follows

1. BCL (Base Class Libraries)

2. CLR (Common Language Runtime)

Base Class Libraries (BCL) are designed by Microsoft. Without BCL we can’t write any code in .NET. So, BCL is also known as the basic building block of .NET Programs. These are installed into the machine when we installed the .NET framework. BCL contains pre-defined classes and these classes are used for the purpose of application development.

CLR stands for Common Language Runtime and it is the core component under the .NET framework which is responsible for converting the MSIL (Microsoft Intermediate Language) code into native code.

In the .NET framework, the code is compiled twice.

1. In the 1^st compilation, the source code is compiled by the respective language compiler and generates the intermediate code which is known as MSIL (Microsoft Intermediate Language) or IL (Intermediate language code), or Managed Code.

2. In the 2^nd compilation, MSIL is converted into Native code (native code means code specific to the Operating system so that the code is executed by the Operating System) and this is done by CLR.

JIT stands for the Just-in-Time compiler. It is the component of CLR that is responsible for converting MSIL code into Native Code. Native code is code that is directly understandable by the operating system.

C# is called a two-stage system because it combines both approaches compilation and interpretation. First C# compiler CSC translates source code into an intermediate language code known as MSIL (Microsoft Intermediate Language) or CIL (Common Intermediate Language) code. But these MSIL or CIL or IL codes are not machine instructions. So, in the second stage, these MSIL or CIL, or IL codes are interpreted by the C# interpreter (One Component of CLR called JIT- Just in Time Compiler). As a result, machine instructions will be generated which are directly executed by the machine. Hence, we are saying C# is both interpreted and compiled language.

Features of C#

Although C# constructs closely follow traditional high-level languages, C and C++ and being an object-oriented programming languages. It has a strong resemblance with Java, it has numerous strong programming features that make it endearing to a number of programmers worldwide. Following is the list of a few important features of C# −

1. Simple: C# is a simple language in the sense that it provides a structured approach (to break the problem into parts), a rich set of library functions, data types, etc.

2. Modern Programming Language: C# programming is based upon the current trend and it is very powerful and simple for building scalable, interoperable, and robust applications.

3. Object-Oriented: C# is an object-oriented programming language. OOPs makes development and maintenance easier whereas in Procedure-oriented programming language it is not easy to manage if code grows as the project size grows.

4. Type-Safe: C# type safe code can only access the memory location that it has permission to execute. Therefore, it improves the security of the program.

5. Interoperability: The interoperability process enables the C# programs to do almost anything that a native C++ application can do.

6. Scalable and Updateable: C# is an automatic scalable and updateable programming language. For updating our application, we delete the old files and update them with new ones.

7. Component Oriented: C# is a component-oriented programming language. It is the predominant software development methodology used to develop more robust and highly scalable applications.

8. Structured Programming Language: C# is a structured programming language in the sense that we can break the program into parts using functions. So, it is easy to understand and modify.

9. Rich Library: C# provides a lot of inbuilt functions that make development fast.

10. Fast Speed: The compilation and execution time of the C# language is fast.