In previous chapter, we have learnt about different view engines. In this chapter, we are going learn about how to do programming with the Razor syntax.

What is razor syntax?

As we all know, with ASP.NET MVC3 Microsoft has introduced new view engine, Razor, which was developed to simplify earlier aspx view engine syntax. Here you can write things @character, which called magic character in razor syntax. In razor view engine, you have .cshtml and .vbhtml for view. Where .cshtml is for C# language and .vbhtml is for VB.NET language.

Fundamentals of razor syntax:

• @character is most important character in the Razor Syntax. You can do many things with @Character. Like to print the current datetime you can use @character as shown below:

  Current DataTime: @DateTime.Now
  

  It will print current date time on the browser.

• You can also write single line statement and variable declaring with @{} syntax as shown below:

  @{ var number = 10; }
  
  
  Number is: @number 
  

  It will print number in browser as below:

• Same way you can also have multiline syntax with @{} syntax like following.

    @{ 
    var firstName = "jalpesh";
    var lastName="vadgama";
    var nameMessage = string.Format("My full name is : {0} {1}", firstName, lastName);
    }

    My name is :@nameMessage 

It will print the name as shown below:

• You can also print a path with “\” character. It supports escape character also.

    @{ var filePath = @"C:\ApplicationFolder\"; }

    The file path is: @filePath

It will print filepath in browser as follows:

Therefore, from all above syntax you can see @ is a magic character for the razor syntax and you can print anything with @character.

Advance syntaxes for razor:

• HTML Expressions in razor syntax:

  Like other view engine, @razor syntax also supports the HTML expression seamless. You can write composite code with html tags and css etc. @ character with razor syntax supports it all.

  Some of the examples are:

    @{ var name = "Jalpesh"; }

    The Name: @name

It will print name in italic characters.

• IF and Else loop with razor syntax:

  Like any other programming language Razor syntax also supports the ‘if and else’ loop. We can write if and loop like following.

  @{
  var message = string.Empty ;
  if(IsPost)
  {
  message = "Page was postback";
  }
  else
  {
  message = "Page was not posback";
  }
  }
  
  
  
  Posback Status:@message 
  

  As you can see in the above code I have checked IsPost with ‘if and else’ loop and assigning a message-to-message variable. In addition, I have a button for postback. Also, I have taken a form with post method on a submit button once we click it will post back the form. So first, we run application without postbacking the form. It will print message in browser like following:

Now once you click on submit button it will look like following:

• For loop in Razor Syntax:

  Razor syntax supports for loops also. Let’s take a simple example of for loop and then we will print a number with help of for loop.

    @for(var i = 1; i < 10; i++)
    {
    
Number @i
    }

This will print number like following in browser:

• For each loop:

  For each loop in razor syntax look like following. Here I am going print all the variable collection.

    @foreach (var variables in Request.ServerVariables)
    {
    }

It will print server variables name like following.

• Switch case statement in Razor Syntax:

  Following is a example of switch case syntax and based on case selected it will print the output.

    @{
    var number=1; var message = string.Empty;
    switch(number)
    {
    case 1:
    message = "Number is 1";
    break;
    case 2:
    message = "Number is 2";
    break;
    default:
    message = "Number is 0";
    break;
    }
    
@message
    }

It will print case 1 message as we have number assigned to 1 in browser like following:

• Commenting in Razor Syntax:

  Like any other languages, Razor syntax also have comments. Following are the syntaxs for single line and multi-line comments.

    @* single line comment. *@

    @*
    Multi - Line
    Comment
    *@

That is it. As you can see Razor syntax is one of easiest syntax to learn. Hope you liked it. Stay tuned for next chapter. In next chapter, we are going to learn about entity framework and how we can use that in ASP.NET MVC.