1. Introduction to C#

Overview of C# Basic Concepts

C# is a fully object-oriented programming language that supports various data types and programming paradigms. Below are key points concerning data types, anonymous types, string interpolation, and type conversion.

Data Types in C#

C# offers four major categories of data types:

1. Value Types (stored on the stack)
   • Examples: bool, char, byte, decimal, double, float, int, long, etc.
   • When you pass a value type to a method or assign it to another variable, its copy is passed or assigned.
   • decimal is more precise than double (e.g., decimal d = 1.2m;).
   • byte can store values from 0 to 255.

2. Reference Types (stored on the heap)
   • When you pass or assign a reference type, the reference (not the copy) is passed.
   • Example: Classes, arrays, etc.

3. Generic Types
   • Templates or type parameters (e.g., List<T>, Dictionary<TKey, TValue>).

4. Pointer Types
   • Less commonly used in high-level C#; often requires unsafe context for direct memory manipulation.

Note:

• Everything in a class is allocated on the heap.

• Everything in a struct is allocated on the stack.

Anonymous Types (and Related Concepts)

1. var
   • Similar to auto in C++.
   • The compiler infers the type at compile time.
   • Because the compiler knows the type, methods and properties become available via IntelliSense when you type . (dot).

2. dynamic
   • The compiler resolves the type at runtime.
   • IntelliSense does not show methods or properties when you type . (dot), because the type isn’t determined until the program is running.

String Interpolation and Verbatim Strings

Instead of concatenating strings like:

// Console.WriteLine("First : " + number1 + "Second : " + number2);

You can use interpolation with the $ symbol:

Console.WriteLine($"First : {number1} Second : {number2}");

To include multiline text or preserve formatting, use the verbatim symbol @ in conjunction with $:

int age = 12;
Console.WriteLine($@"
Hello
This program's age is {age}
                Developer
C++

    C#
");

This approach keeps the original formatting, including line breaks and whitespace.

Converting Data

1. Convert
   • Methods like Convert.ToInt32(string) convert strings to numerical types.
   • If conversion fails, an exception is thrown.

2. Parse
   • Methods like int.Parse(string) also throw an exception on failure.

3. TryParse
   • Methods like int.TryParse(string, out int result) return a boolean (true if successful, false otherwise).
   • If the conversion is successful, the result is stored in the result variable; if not, you can handle it gracefully.

Reference

The content in this document is based on the original notes provided in Azerbaijani. For further details, you can refer to the original document using the following link:

Original Note - Azerbaijani Version