The following are the benefits of using ADO.NET in .NET 4.0 are as follows:

 =>   Language-Integrated Query (LINQ) - Adds native data-querying capabilities to .NET languages by using a syntax similar to that of SQL. This means that LINQ simplifies querying by eliminating the need to use a separate query language. LINQ is an innovative technology that was introduced in .NET Framework 3.5.
 =>   LINQ to DataSet - Allows you to implement LINQ queries for disconnected data stored in a dataset. LINQ to DataSet enables you to query data that is cached in a DataSet object. DataSet objects allow you to use a copy of the data stored in the tables of a database, without actually getting connected to the database.
=>   LINQ to SQL - Allows you to create queries for data stored in SQL server database in your .NET application. You can use the LINQ to SQL technology to translate a query into a SQL query and then use it to retrieve or manipulate data contained in tables of an SQL Server database. LINQ to SQL supports all the key functions that you like to perform while working with SQL, that is, you can insert, update, and delete information from a table.
=>   SqlClient Support for SQL Server 2008 - Specifies that with the starting of .NET Framework version 3.5 Service Pack (SP) 1, .NET Framework Data Provider for SQL Server (System.Data.SqlClient namespace) includes all the new features that make it fully compatible with SQL Server 2008 Database Engine.
=>   ADO.NET Data Platform - Specifies that with the release of .NET Framework 3.5 Service Pack (SP) 1, an Entity Framework 3.5 was introduced that provides a set of Entity Data Model (EDM) functions. These functions are supported by all the data providers; thereby, reducing the amount of coding and maintenance in your application. In .NET Framework 4.0, many new functions, such as string, aggregate, mathematical, and date/time functions have been added.

When a class is derived from another class, then the members of the base class become the members of the derived class. The access modifier used while accessing members of the base class specifies the access status of the base class members inside the derived class.

The syntax to inherit a class from another class in C# is as follows:
class MyNewClass : MyBaseclass

The JIT compiler is an important element of CLR, which loads MSIL on target machines for execution. The MSIL is stored in .NET assemblies after the developer has compiled the code written in any .NET-compliant programming language, such as Visual Basic and C#.

JIT compiler translates the MSIL code of an assembly and uses the CPU architecture of the target machine to execute a .NET application. It also stores the resulting native code so that it is accessible for subsequent calls. If a code executing on a target machine calls a non-native method, the JIT compiler converts the MSIL of that method into native code. JIT compiler also enforces type-safety in runtime environment of .NET Framework. It checks for the values that are passed to parameters of any method.

For example, the JIT compiler detects any event, if a user tries to assign a 32-bit value to a parameter that can only accept 8-bit value.

.NET Framework provides enormous advantages to software developers in comparison to the advantages provided by other platforms. Microsoft has united various modern as well as existing technologies of software development in .NET Framework. These technologies are used by developers to develop highly efficient applications for modern as well as future business needs. The following are the key components of .NET Framework:

 =>   .NET Framework Class Library
 =>   Common Language Runtime
 =>   Dynamic Language Runtimes (DLR)
 =>   Application Domains
 =>   Runtime Host
 =>   Common Type System
 =>   Metadata and Self-Describing Components
 =>   Cross-Language Interoperability
 =>  .NET Framework Security
 =>   Profiling
 =>   Side-by-Side Execution

.NET Framework is a complete environment that allows developers to develop, run, and deploy the following applications:

 => Console applications
 => Windows Forms applications
 => Windows Presentation Foundation (WPF) applications
 => Web applications (ASP.NET applications)
 => Web services
 => Windows services
 => Service-oriented applications using Windows Communication Foundation (WCF)
 => Workflow-enabled applications using Windows Workflow Foundation (WF)

The mysqli extension , or as it is sometimes known, the MYSQL improved extension ,was developed to take advantage of new features found in MYSQL systems versions 4.1.3 and later.

The mysqli extension has a number of benfits,the key enhancements over the mysql extension being:
=> Object-oriented interface
=> Support for prepared statements
=> Support for multiple statements
=> Support for transactions
=> Enhanced debugging capabilities
=> Embedded server support

sort() , rsort(), asort()
ksort()   , usort()
arsort()  , uksort()
natsort() , natcasesort()
array_multisort()

unlink()-deletes the given file from the file system.
unset() -makes a variable undefined.