> For the complete documentation index, see [llms.txt](https://eleven-fifty-academy.gitbook.io/dotnet-100-prework-gitbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://eleven-fifty-academy.gitbook.io/dotnet-100-prework-gitbook/part-3-c-fundamentals/2.0-variables.md).

# 2.0: Variables

In this module we'll discuss declaring and initializing variables.

## File Location

1. Right click on the solution you made in the first module, go to **Add > New Project**.
2. Select **Console App (.NET Framework)**.
3. Name it `02_variables`.
4. You will write your code for this module within `Program.cs` of that project. Go ahead and open that file now.

## Declaring and Initializing Variables

Let's look at how to **declare** variables:

Here is some code:

```csharp
class Program
{
    static void Main(string[] args)
    {
        //1    //2          //3
        string firstName = "Paul";
        Console.WriteLine(firstName);
        Console.ReadLine();
    }
}
```

1. To **declare** a variable, you need a **type**. In this case, we are using a string type. More on types later.
2. We also need a name for the variable. In this case it is`firstName`. The **name** of the variable is up to you. A few considerations:
   * It should be descriptive enough that you can easily remember what it's for, but not too long.
   * It will be camelCased i.e. `birthYear` or `isMarried`. This means that the first word is lowercase and each subsequent word is uppercase.
3. We also initialize the value of the variable with a string value in quotes. 

## Declaration Only

There are times when we will only want to *declare* a variable.

```csharp
class Program
{
    static void Main(string[] args)
    {
        string firstName = "Paul";
        Console.WriteLine(firstName);
        //1       //2
        string lastName;
                        //3
        Console.WriteLine(lastName);

        Console.ReadLine();
    }
}
```

We are saying there is a thing called `birthYear` and the value **type** is an `int`, but we have not assigned the **value**:

* To **initialize** a variable, you need a **type**, a **name**, and a **value**.
* You can initialize the variable on the same line that you declare it, or later, on another line.

```csharp
static void Main(string[] args)
{
    int birthYear = 1990;
}
```

In your `Program.cs` file in the `02_variables` project, practice declaring and initializing variables of different types with different variable names and values.