by Dinesh Thakur Category: Introduction to C#

C# has a strong feature in which we can define more than one class with the Main method. Since Main is the entry point for the program execution, there are now more than one entry points. In fact, there should be only one entry point. Which will be resolved by specifying which Main is to be used to the compiler at the time of compilation as shown below:

 
by Dinesh Thakur Category: Introduction to C#

Let's begin in the traditional way, by looking at the code of a Hello World program.

1. using System;

2. public class HelloWorld

3. {

4. public static void Main()

5. {

6. II This is a single line comment

7. /* This is a

8. multiple

9. line comment */

10. Console.WriteLine("Hello World! ");

11. }

12. }

 
by Dinesh Thakur Category: Introduction to C#

When many people work in creating the same program, it could be difficult to keep track of the names of various classes. If more than one programmer creates a class with the same name in the same program, there would be conflict and the program would not work. The solution to avoid this situation is to delimit sections of code with names.

 
by Dinesh Thakur Category: Introduction to C#

The Function defined with in class is called method. It is a code designed to work on the member data of class.

 

Methods are operations associated with types. To provide a type with methods is to give it some useful functionality. Often this functionality is made generally available, so that it can be utilized by other types.

 
by Dinesh Thakur Category: Introduction to C#

An enumeration is a special set of numeric type string literals which considered as a constants.

An enumeration is a special kind of value type limited to a restricted and unchangeable set of numerical values. By default, these numerical values are integers, but they can also be longs, bytes, etc. (any numerical/value except char) as will be illustrated below.

 
by Dinesh Thakur Category: Introduction to C#

Structure is a user-defined value type which encapsulates member data and member function.

A struct is a user-defined value type. It is declared in a very similar way to a class, except that it can't inherit from any class, nor can any class inherit from it (as mentioned\ previously, however, all value types do inherit from System.object), The following example shows a partial declaration for a 'Coordinate' struch.

 
by Dinesh Thakur Category: Introduction to C#

C# uses a series of words, called keywords, for its internal use. This means that you must avoid naming your objects using one of these keywords.

 
by Dinesh Thakur Category: Introduction to C#

Command line arguments are parameters supplied to the Main method at the time of invoking it for execution. To understand the concepts see the example given below:

Program of Command line argument to accept name from the command line and writes to the console. (Sample.cs)

 
by Dinesh Thakur Category: Introduction to C#

In the body of a method, you can also declare variables that would be used internally. A variable declared in the body is referred to as a local variable. It cannot be accessed outside of the method it belongs to. After declaring a local variable, it is made available to the method and you can use it.

 
by Dinesh Thakur Category: Introduction to C#

Identifiers refer to the names of variables, functions arrays, classes, etc. created by programmer. They are fundamental requirement of any language. Each language has its own rules for naming these identifiers.

 
by Dinesh Thakur Category: OOP's in C#

Inheritance is a mechanism of sharing the members among the classes. Inheritance means taking an existing class and adding functionality by deriving a new class from it. The class you start with is called the base class, and the new class you create is called the derived class.

 
by Dinesh Thakur Category: OOP's in C#

One can create new reference types by defining classes. Classes provide templates' from which these direct instances are generated. Where we appeal to the relation between a class and its corresponding reference type instances we shall say that a class specifies the type (also that the class specifies the constitutive elements of the type)

 
by Dinesh Thakur Category: OOP's in C#

Method overriding means same name methods in different classes.

Polymorphism is a feature to use one name in many forms. There ·Polymorphism can be achieved in following ways in C#:

 
by Dinesh Thakur Category: OOP's in C#

Object-Oriented programming emphasis on data rather than function.

Object-Oriented programming was developed due to the limitations of the traditional programming approaches. The traditional programming approaches, such as Pascal, C, BASIC, FORTRAN and etc., are basically called procedural-oriented programming languages.

 
by Dinesh Thakur Category: OOP's in C#

Constructor is method of class to allocate the memory of object and initialize the variables of class.

 

When you declare a variable of a class, a special method must be called to initialize the members of that class. This method is automatically provided for every class and it is called a constructor.

 
by Dinesh Thakur Category: Advanced C#

Another important and exciting feature object-oriented programming is Operator overloading. C# supports the concept of operator overloading.

Operator overloading is a concept in which operator can defined to work with the userdefined data types such as structs and classes in the same way as the pre-defined data types.



 
by Dinesh Thakur Category: Advanced C#

The Collection namespace of System contains many classes and interfaces, which provides to define various collections of objects. These interfaces and classes are useful for every programmer to develop big or large applications.

 
by Dinesh Thakur Category: Advanced C#

In object-oriented languages, objects expose encapsulated functions called methods. Methods are encapsulated functions which run when they are invoked.

Sometimes, however, we think of the process of method invocation more grandly. In such a case, the method invocation is termed an 'event', and the running of the method is the 'handling' of the event. An standard example of an event is a user's selection of a button on a graphical user interface; this action may trigger a number of methods to 'handle' it

 
by Dinesh Thakur Category: Advanced C#

An indexer is a member that enables objects to be indexed in the same as an array.

If properties are 'virtual fields', indexers are more like 'virtual arrays'. Indexers permit instances of a class or struct to be indexed in the same way as arrays. Indexers are similar to properties except that their accessors take parameters. They allow a class to emulate an array, where the elements of this array are actually dynamically generated by function calls.

 
by Dinesh Thakur Category: Advanced C#

Delegate is a method template which used to implement the concept of function pointer.

 

The C and C++ languages are having the concept of function pointer. This was even more useful when programming for the Microsoft Windows operating systems because the Win32 library relies on the concept of callback functions. Callback functions are used in Microsoft Windows programming to process messages. For this reason and because of their functionality, callback functions were carried out in the .NET Framework but they were defined with the name of delegate.



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.