DOT NET

What is  VB.NET?

 DOT NET Framework is a software framework developed by Microsoft that runs primarily on Microsoft Windows. It includes a large library and provides language inseparability across several programmings.

DOTNET OVERVIEW :

• To provide a consistent object-oriented environment to develop applications.
• To provide a code execution environment that simplifies deployment and version.
• To provide a code execution environment that guarantees the safety of the code that is executing. This includes both code developed internally by an organization or for code developed by 3rd party vendors.
• To provide a code execution environment that eliminates the issues faced by scripted environments with respect to performance.
• To provide a common programming model where the choice of a programming language becomes a matter of choice.

Common Language Runtime

• The CLR is the platform on which applications are hosted and executed. The CLR also provides a set of services that applications can use to access various resources. Since this runtime "manages" the execution of your code, code that works on the CLR is called as managed code. Any other code, you guessed it, is called unmanaged code.
  Compilers and tools expose the CLR's functionality and enable you to write code that benefits from this managed execution environment. To enable the runtime to provide services to managed code, language compilers must also emit metadata that describes the types that we develop in .NET. This metadata is stored along with the type file and makes it "self-describing". Using this information, When compilers emit code to run on the CLR, they do not emit machine language code. Rather, an intermediate language code is used called Microsoft Intermediate Language .MSIL is like an object-oriented version of assembly language and is platform independent. It has a rich set of instructions that enable efficient representation of the code. When a code starts to execute, a process knowing as Just in Time Compilation converts the MSIL code into the native processor instructions of the platform. 

.NET for Java developers

Leverage your existing knowledge of Java solutions architecture to build Windows solutions based on the .NET Framework and C#.

DOTNET Framework

.NET Framework   is a developed by that runs primarily on It includes a large and provides   across several. Programs written for .NET Framework execute in a environment  known  CLR. That provides services such as security, and. The class library and the CLR together constitute .NET Framework.

.NET Framework's provides, development, numeric, and Programmers produce software by combining their own with .NET Framework and other libraries. .NET Framework is intended to be used by most new applications created for the Windows platform.

Memory management

.NET Framework CLR frees the developer from the burden of managing memory it handles memory management itself by detecting when memory can be safely freed. Instantiations of .NET types are allocated from the managed heap; a pool of memory managed by the CLR. As long as there exists a reference to an object, which might be either a direct reference to an object or via a grap of objects, the object is considered to be in use. When there is no reference to an object, and it cannot be reached or used, it becomes garbage, eligible for collection. .NET Framework includes a garbage collector which runs periodically, on a separate thread from the application's thread, that enumerates all the unusable objects and reclaims the memory allocated to them.

.NET Garbage Collector   is a non-deterministic, compacting, mark-and-sweep garbage collector. The GC runs only a certain amount of memory has been used or there is enough pressure for memory on the system. A guaranteed when the conditions to reclaim memory are reached, the GC runs are non-deterministic. BOTH DOTNET application has a set of roots, which are pointers to objects on the managed heap.  These include references to static objects and objects defined as local variables or method parameters currently in scope, as well as objects referred to by CPU registers. When the GC runs, it pauses the application, and for each object referred to in the root, it recursively enumerates all the objects reachable from the root objects and marks them as reachable. It uses CLI metadata and reflection to discover the objects encapsulated by an object, and then recursively walk them. It then enumerates all the objects on the heap using reflection. All objects not marked as reachable are garbage.