**Course Title:** Mastering C#: From Fundamentals to Advanced Programming **Section Title:** Introduction to C# and .NET Framework **Topic:** Basic C# syntax: Variables, data types, operators. Welcome to the world of C# programming. In this topic, we will delve into the fundamental syntax of C#, covering variables, data types, and operators. Understanding these concepts is crucial to building a strong foundation in C# programming. ### Variables In C#, a variable is a storage location that holds a value. Variables have a name, a data type, and a value. The basic syntax for declaring a variable is: ```csharp data-type variable-name; ``` For example: ```csharp int age; ``` In this example, `int` is the data type, `age` is the variable name, and `age` can hold integer values. You can also assign a value to a variable when you declare it: ```csharp int age = 25; ``` #### Declaring Multiple Variables You can declare multiple variables of the same data type in a single statement: ```csharp int age, salary, experience; ``` Or, you can assign different values to each variable: ```csharp int age = 25, salary = 50000, experience = 5; ``` #### Variable Naming Conventions Variable names in C# should: * Begin with a letter or an underscore (_) * Contain only letters, numbers, and underscores * Not be a C# keyword * Be descriptive and meaningful Example: ```csharp int customerAge; string customerName; ``` ### Data Types C# has several built-in data types, including: * **Integer Types**: `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong` * **Floating-Point Types**: `float`, `double`, `decimal` * **Boolean Type**: `bool` * **Character Type**: `char` * **String Type**: `string` You can use the `typeof` operator to determine the type of a variable: ```csharp Console.WriteLine(typeof(int)); // Output: System.Int32 ``` For more information on data types, visit the official [Microsoft documentation](https://docs.microsoft.com/en-us/dotnet/csharp/fundamentals/data-types/). ### Operators Operators in C# are used to perform operations on variables and values. Here are the basic operators: * **Arithmetic Operators**: `+`, `-`, `*`, `/`, `%`, `++`, `--` * **Comparison Operators**: `==`, `!=`, `>`, `<`, `>=` , `<=` * **Logical Operators**: `&&`, `||`, `!` * **Assignment Operators**: `=`, `+=`, `-=`, `*=`, `/=`, `%=`, `&=`, `^=`, `|=`, `<<=`, `>>=` Here's an example of using arithmetic operators: ```csharp int x = 10; int y = 2; int sum = x + y; // sum = 12 int product = x * y; // product = 20 ``` And here's an example of using comparison operators: ```csharp bool isEqual = x == y; // isEqual = false bool isGreater = x > y; // isGreater = true ``` **Example Code** Here's an example code snippet that demonstrates the use of variables, data types, and operators: ```csharp using System; class Program { static void Main() { // declare and initialize variables int age = 25; double salary = 50000.0; string name = "John Doe"; // perform arithmetic operations double tax = salary * 0.2; // use comparison operators bool isEmployed = salary > 0; Console.WriteLine($"Name: {name}"); Console.WriteLine($"Age: {age}"); Console.WriteLine($"Salary: {salary:C}"); Console.WriteLine($"Tax: {tax:C}"); Console.WriteLine($"Is Employed: {isEmployed}"); } } ``` **Practice Exercise** Try to modify the example code above to calculate and display the employee's net salary after deducting taxes. **What's Next?** In the next topic, we will explore **Introduction to Namespaces and Assemblies**. **Leave a Comment or Ask for Help** If you have any questions or need help with any of the concepts covered in this topic, feel free to leave a comment below.