Introduction to C#

C# is a high-level, general-purpose, compiled programming language.

History

It was developed and is maintained by Microsoft.

C# Resources

• Getting Started: Language Download
• Getting Started: Development Tools
• Getting Started: Testing
• Getting Started: Deployment
• Beginner Tutorials
• Intermediate Tutorials
• Advanced Tutorials
• Good Beginner Blog
• Good Intermediate Blog
• Good Advanced Blog
• Official Documentation

Quick Reference – C#

Here is a quick reference for the basics of C#…

Hello World in C#

using System;
					
public class Program
{
  public static void Main()
  {
    Console.WriteLine("What is your name?");
    string yourName = Console.ReadLine();
    Console.WriteLine("Hello " + yourName + "!");
  }
}

C#: Basic Syntax

Variables & Data Types

  bool    (true/false)
  byte    (8 bit)
  int     (32 bit)
  uint
  short   (16 bit)
  ushort
  long    (64 bit)
  ulong
  float   (32 bit)
  double  (64 bit)
  decimal (precise decimal with 29 significant digits)
  char    (single unicode character)
  string
  DateTime
  object

Branching

if (condition) {
  // do something
} else { 
  // do something else
}

Arrays

int[] primeNumbers = { 2, 3, 5, 7, 11 };

Lists

List primeNumbers = new List {2, 3, 5, 7, 13};

Dictionaries

Dictionary<string, string> dictionaryName = new Dictionary<string, string>();

Loops

You can loop through all the items in an array:

string[] myList = {"one", "two", "three", "four", "five"};

foreach (string item in myList) {
  Console.WriteLine(item);
}

You can loop a fixed number of times:

for (int i = 0; i < 5; i++) {
  Console.WriteLine(i);
}

You can loop while a condition is true:

while (true) {
  // do something that may change the condition
}

You can loop until a condition is false (always loops once):

do {
  // do something that may change the condition
} while (true);

C#: Object-Oriented Syntax

Classes

class Animal {
  public string Species;
  public string Name;
  public string Sound;
}

Objects

Animal myPet = new Animal();

myPet.Species = "dog";
myPet.Name = "Fido";
myPet.Sound = "Bow-wow";

Methods

class MyCalculator {
  public int Add(int num1, int num2) {
    return num1 + num2;
  }
}

Constructors

class Animal {
  public string Species;
  public string Name;
  public string Sound;

  public Animal(string species, string name, string sound) {
    Species = species;
    Name = name;
    Sound = sound;
  }
}

Animal myPet = new Animal("dog", "Fido", "Bow-wow");
Animal yourPet = new Animal("cat", "Garfield", "Screech! Hiss!");

Favorite Books on C#