Chapter 21: Razor – C# Variables

Razor – C# Variables — that is, how you declare, use, and work with variables inside .cshtml Razor files when using C#.

This is one of the first things every Razor beginner must master, because almost every dynamic page starts with variables: names, prices, dates, lists, user data, flags, calculations, etc.

I’m going to explain it like we’re sitting together at a table in Charminar area, writing code on paper, running it mentally, and debugging together — very slowly, with lots of real examples.

1. The Golden Rule of Variables in Razor (Write this down!)

In Razor .cshtml files using C#:

• Variables are declared and used exactly the same way as in normal C# — same rules, same types, same scope rules.
• The only difference is where you place them:
  • Inside @{ … } code blocks → normal C# variables (most common)
  • Inline with @ → you can use them directly in HTML output

There is no special “Razor variable type” — they are pure C# variables.

2. Three Main Places Where You Meet Variables in Razor

Place 1 – Code Blocks at the Top (Most Common)

→ Rules inside @{ … }:

• Use var (implicit typing — most popular) or explicit types (string, int, decimal, etc.)
• End statements with ;
• Case-sensitive (city ≠ City)
• Normal C# scope: variables declared here are available below in the same file (and in layouts/sections if passed via Page or ViewData)

Place 2 – Inline Expressions with @

Once declared, you can use variables anywhere in HTML with just @:

→ @variableName → Razor evaluates it and prints .ToString() result → @(expression) → use parentheses when it’s a calculation or complex expression

Place 3 – Sharing Variables with Layout / Partial Views

→ Page is a dynamic object — you can add any property you want (Page.anything = value;)

3. Common Variable Types & How They Look in Razor

4. Full Realistic Example – Mini Product Card Page

→ Every line shows variables being:

• Declared (var …)
• Calculated (discountedPrice = …)
• Formatted (.ToString(“N2”), .ToString(“C”))
• Used in conditions (@if (isInStock))
• Looped (@foreach)
• Printed (@productName, @discountedPrice, etc.)

5. Teacher Tips & Common Beginner Mistakes

• Always declare variables before using them in HTML (top-to-bottom execution)
• Use var most of the time — cleaner and Razor-friendly
• For money → always use decimal (not double — floating point issues)
• When reading from forms: int qty = Request[“qty”].AsInt(0); — never trust Convert.ToInt32()
• Scope: variables in @{ } at top are available everywhere below in the same file
• Avoid very long code blocks — keep logic clean, move complex code to PageModel (in modern Razor Pages)

Summary – Blackboard Close

ASP.NET Razor – C# Variables means:

• Declare them exactly like normal C# (var x = value;, string name = “Hyderabad”;, int count = 42;)
• Use @{ … } blocks at the top of the file for logic & declarations
• Print/use them anywhere in HTML with simple @variable or @(expression)
• Share between page & layout using Page.variableName = value;
• Razor treats them as normal C# variables — no special magic type

Now you can create, calculate, format, loop, and display any data you want!

Next step?

• Want to see how variables work with forms (reading from Request)?
• Or variables in loops & conditions with more examples?
• Or move to @model and strongly-typed variables in Razor Pages?

Just tell me — you’re doing great! Keep coding strong from Hyderabad! 🚀🇮🇳