C # Basic syntax

C#Basic Syntax

C # is an object-oriented programming language. In the object-oriented program design method, the program consists of various objects interacting with each other. Objects of the same kind usually have the same type, or, in the same class.

For example, take the Rectangle (Rectangle) object as an example. It has the length and width properties. Depending on the design, it may be necessary to accept these property values, calculate the area, and display the details.

Let's take a look at the implementation of a Rectangle (rectangle) class and discuss the basic syntax of C #:

Using System;Namespace Rectangleapplication{ Class Rectangle { Member variables DoubleLength; DoubleWidth; Public void Acceptdetails() {Length= 4.5;Width= 3.5; } Public Double Getarea() { ReturnLength*Width; } Public void Display() { Console.WriteLine("Length: {0}",Length); Console.WriteLine("Width: {0}",Width); Console.WriteLine("Area: {0}", Getarea()); } } Class Executerectangle { Static void Main (string[] Args { rectangle R = new rectangle ();  R. Acceptdetails  R. Displayconsole. Readline} }} 
    /span>                

When the above code is compiled and executed, it produces the following results:

length:4.5width:3.5area:15.75

usingKey words

The first statement in any C # program is:

UsingSystem; 

The using keyword is used to include namespaces in your program. A program can contain multiple using statements.

classKey words

The class keyword is used to declare a category.

Comments in C #

Comments are used to interpret the code. The compiler ignores the entry for the comment. In a C # program, a multiline comment starts with/* and terminates as a character, as follows:

/* This program demonstratesthe basic syntax of C # programming Language */

A single-line comment is denoted by a '//' symbol. For example:

}//end class Rectangle    

Member variables

A variable is a property or data member of a class that is used to store data. In the above program, theRectangle class has two member variables, named length and width.

member functions

A function is a series of statements that perform a specified task. The member functions of a class are declared within a class. Our example class Rectangle contains three member functions: acceptdetails,Getarea , and Display.

Instantiate a class

In the above program, class Executerectangle is a class that contains the Main () method and instantiates the Rectangle class.

Identifier

Identifiers are used to identify a class, variable, function, or any other user-defined item. In C #, the naming of a class must follow the following basic rules:

• Identifiers must begin with a letter or underscore (_) followed by a series of letters, Numbers (0-9), or underscores (_). The first character in an identifier cannot be a number.
• The identifier must not contain any embedded spaces or symbols, such as? - +! @ #% ^ & * () [] {}. ; : " ‘ / \。 However, you can use the underscore (_).
• The identifier cannot be a C # keyword.

C # Keywords

The keyword is a predefined reserved word for the C # compiler. These keywords cannot be used as identifiers, but if you want to use these keywords as identifiers, you can prefix them with the @ character before the keyword.

In C #, some identifiers have special meanings in the context of the code, such as Get and set, which are called contextual keywords (contextual keywords).

The following table lists the reserved keywords (Reserved Keywords) and the contextual keywords (contextual Keywords) in C #:

Reserved keywords
Abstract	As	Base	bool	Break	Byte	Case
Catch	Char	Checked	Class	Const	Continue	Decimal
Default	Delegate	Do	Double	Else	Enum	Event
Explicit	extern	False	Finally	Fixed	Float	For
Foreach	Goto	If	Implicit	Inch	In (generic Modifier	Int
Interface	Internal	Is	Lock	Long	Namespace	New
Null	Object	operator	Out	Out (Generic Modifier	Override	Params
Private	Protected	Public	ReadOnly	Ref	Return	SByte
Sealed	Short	sizeof	Stackalloc	Static	String	struct
Switch	This	Throw	True	Try	typeof	UInt
ULong	Unchecked	Unsafe	UShort	Using	Virtual	void
Volatile	While
Context keywords
Add	Alias	Ascending	Descending	Dynamic	From	Get
Global	Group	Into	Join	Let	By	Partial (type)
Partial (method)	Remove	Select	Set

C # Basic syntax