IronCodeMan

Concepts for C#

C# is a modern, object-oriented programming language developed by Microsoft as part of its .NET framework. It combines the power and flexibility of C++ with the simplicity of Visual Basic. C# is designed for building robust, scalable applications across various platforms, including desktop, web, and mobile. It features strong typing, automatic memory management through garbage collection, and a rich standard library. With features like LINQ (Language-Integrated Query) and async/await for asynchronous programming, C# enables developers to write clean, efficient code with high productivity. Additionally, C# is closely integrated with Microsoft technologies, making it a popular choice for Windows application development.

Print Text

public class HelloWorld {
  public static void Main(String[] args) {
    Console.WriteLine("Hello World!");
  }
}

Comments

// one line comment

/*
multi 
line 
comment
*/

Variables

int carCount = 2;
string name = "Joe";
bool isPurple = true;

Data Types

int carCount = 2;
uint age = 15;
short seaLevel = -10000;
long usBudget = 11000000000;
ulong lightSpeed = 11799312874;
float myGPA = 3.45F;
double piValue = 3.14159265D;
char lastLetter = 'Z';
bool isMale = true;
string myName = "Joe";

Math Op

int carCount = 6;
int truckCount = 3;

int total = carCount + truckCount;
Console.WriteLine(total + "\n");

int subtract = carCount - truckCount;
Console.WriteLine(subtract + "\n");

int multiple = carCount * truckCount;
Console.WriteLine(multiple + "\n");

int divisible = carCount / truckCount;
Console.WriteLine(divisible + "\n");

// performs division and gets remainder which is 0
int modulo = carCount % truckCount;
Console.WriteLine(modulo + "\n");

Math Functions

double power = Math.pow(3.0, 6.0);
Console.WriteLine(power);

double root = Math.Sqrt(16.0);
Console.WriteLine(root);

double floorVal = Math.Floor(3.14);
Console.WriteLine(floorVal);

double ceilVal = Math.Ceiling(4.3);
Console.WriteLine(ceilVal);

double roundVal = Math.Round(3.4);
Console.WriteLine(roundVal);

// random number from 0 to 100
Random rand = new Random();
int ranNum = rand.Next(0, 101);
Console.WriteLine(ranNum);

If/Else

int carCount = 6;
    
if (carCount > 3) {
  Console.WriteLine("More than three cars");
} else if (carCount == 3) {
  Console.WriteLine("Equal to three cars");
} else {
  Console.WriteLine("Less than three cars");
}

Ternary

int carCount = 3;

string result = (carCount > 2) ? "Yes" : "No";
Console.WriteLine(result);

Switch

int carCount = 3;

switch (carCount) {
  case 1:
    Console.WriteLine("One car");
    break;
  case 2: 
    Console.WriteLine("Two cars");
    break;
  case 3: 
    Console.WriteLine("Three cars");
    break;
  default: 
    Console.WriteLine("More than three");
    break;

}

Functions

static int handleCars(int cars, int wheels) {
  int total = cars * wheels;
  return total;
}

int result = handleCars(3, 4);
Console.WriteLine(result);

Interpolation

string name = "Joe";
string car = "Mazda";
string result =
  format("{} drives a {}", name, car);
Console.WriteLine(result);

Type Casting

String squareA(int length) {
  double result = (double)(Math.Pow(length, 2));
  return result.ToString();
}

String squareL = "4";
int convertedVal = int.Parse(squareL);

String area = squareA(convertedVal);
Console.WriteLine(area);

Date and Time

// get current date
DateTime now = DateTime.Now;
Console.WriteLine(now);

// find tim in milliseconds
long millitime = (long)(
  now - new DateTime(1970, 1, 1)
).TotalMilliseconds;

Console.WriteLine(millitime);

// create date time obj
DateTime date = new DateTime(2023, 11, 20);
Console.WriteLine(date.ToString());

// finds the current year
String currentYear = 
  DateTime.Now.Year.ToString();
Console.WriteLine(currentYear);

// finds current date and formats it
String currentDate = 
  DateTime.Now.ToString("MM/dd/yyyy");
Console.WriteLine(currentDate);

Classes

using System;
using System.Collections.Generic;

public class Cars {
  protected List<string> carList = new List<string>();
  
  public void addCar(string car) {
    carList.Add(car);
  }
  
  public void removeFirst() {
    carList.RemoveAt(0);
  }
  
  public string getFirstVal() {
    if (carList.Count > 0) {
      return carList[0];
    }
    return "";
  }
  public static void Main(string[] args) {
    Cars newList = new Cars();
    newList.addCar("Honda");
    newList.addCar("Mazda");
    newList.addCar("Toyota");
    newList.removeFirst();
    
    string firstCar = newList.getFirstVal();
    Console.WriteLine(firstCar);
  }
}

Inheritance

class User {
  protected string username;
  protected string password;
  
  public User(
    string Username,
    string Password
  ) {
    username = Username;
    password = Password;  
  }
}

class Admin: User {
  protected string id;
  
  public Admin(
    string username,
    string password,
    string Id
  ): base(username, password) {
    id = Id;
  }
  
  public string getUsername() {
    return username;
  }
  
  public string getAdminID() {
    return id;
  }
}

public class Test {
  public static void Main(string[] args) {
     Admin newAdmin = new Admin(
      "alpha0",
      "pw1",
      "1FE"
    );

    Console.WriteLine(
      newAdmin.getUsername()
    );

    Console.WriteLine(
      newAdmin.getAdminID()
    );
  }
}

Method Overload

class UserForm {
  public string formA = "alpha";
  public string formB = "beta";
  public string formC = "gamma";
  public string formD = "epsilon";
  
  public string getForm(int age) {
    if (age > 65) {
      return formA;
    }
    return formB;
  }

  public string getForm(string id) {
    if (id == "1FE") {
        return formA;
    }
    return formC;
  }
  
  public string getForm(
    bool isMilitary,
    bool isNasa
  ) {
    if (isMilitary || isNasa) {
      return formD;
    }
    return formA;
  }
}

UserForm form = new UserForm();
      
int myAge = 67;
string myId = "1FE";
bool veteran = false;
bool nasa = true;

string form1 = form.getForm(myAge);
string form2 = form.getForm(myId);
string form3 = form.getForm(veteran, nasa);

Console.WriteLine(form1 + "\n");
Console.WriteLine(form2 + "\n");
Console.WriteLine(form3 + "\n");

Abstract Class

abstract class Animation {
  public abstract void walk();
  public abstract void run();
  public abstract void idle();
}

class Human: Animation {
  public override void walk() {
    Console.WriteLine("Human walks" );
  }
  public override void run() {
   Console.WriteLine("Human runs" );
  }
  public override void idle() {
   Console.WriteLine("Human idles" );
  }
}

class Zombie: Animation {
  public override void walk() {
    Console.WriteLine("Zombie walks" );
  }
  public override void run() {
    Console.WriteLine("Zombie runs" );
  }
  public override void idle() {
    Console.WriteLine("Zombie idles" );
  }
}

Human player = new Human();
player.walk();

Zombie boss1 = new Zombie();
boss1.run();

Static Class

public static class Helper {
  public static double CircleA(int radius) {
    double power = Math.pow(radius, 2);
    return (double)(3.14 * power);
  }
  public static double SquareA(int length) {
    return (double)(Math.pow(length, 2));
  }
};

double circle = Helper.CircleA(3);
Console.WriteLine(circle);
      
double square = Helper.SquareA(4);
Console.WriteLine(square);

Arrays/Lists

string[] names = new string[] {"Joe", "Alex", "Box"};
names[1] = "Tom";
string name = names[1];
int numItems = names.Length;

Console.WriteLine(name);
Console.WriteLine(numItems);

Array Methods

List<string> cars = new List<string>();
cars.Add("Honda");
cars.Add("Mazda");
cars.Add("Toyota");

// check existence of key Mazda
Console.WriteLine(cars.Contains("Mazda"));

// removes item at index 1
Console.WriteLine(cars[1] );
cars.RemoveAt(1);
Console.WriteLine(cars[1] );

// removes elements with matching balue 
cars.Remove("Honda");
Console.WriteLine(cars[0]);

// count number of elements
Console.WriteLine(cars.Count);

Concatenation

List<string> carsListKr =
  new List <string>();

carsListKr.Add("Kia");
carsListKr.Add("Hyundai");
carsListKr.Add("Daewoo");

List<string> carsListJp =
  new List <string>();

carsListJp.Add("Honda");
carsListJp.Add("Mazda");
carsListJp.Add("Toyota");

List<string> combined =
  new List<string>();

combined.AddRange(carsListKr);
combined.AddRange(carsListJp);

Console.WriteLine(combined[1]);
Console.WriteLine(combined[4]);

Sort Method

using System.Collections.Generic;

List<int> ages = new List<int>();

ages.Add(5);
ages.Add(3);
ages.Add(1);
ages.Add(6);
ages.Add(7);
ages.Add(4);
ages.Add(19);
ages.Sort();

for (int i = 0; i < ages.Count; i++) {
  Console.WriteLine(ages[i] + "\n");
}

Objects

public class User {
  public string first;
  public string last;
  public int age;
  public bool retired;
  public string[] carBrands;
  
  public User (
    string First,
    string Last,
    int Age,
    bool Retired,
    string[] CarBrands
  ) {
    first = First;
    last = Last;
    retired = Retired;
    carBrands = CarBrands;
  }
  
  public string fullName() {
    return $"{first} {last}";
  }
    
  public static void Main(string[] args) {
    string[] brands = {"Mazda", "Toyota"};
    User user = new User (
      "Joe",
      "Doe",
      23,
      false,
      brands
    );
    
    Console.WriteLine(user.first);
    Console.WriteLine(user.carBrands[1]);
    Console.WriteLine(user.fullName());
  }
}

Maps (Key/Value)

using System.Collections.Generic;

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

carMap.Add("Joe", "Toyota");
carMap.Add("Bob", "Mazda");
carMap.Add("Tom", "Ford");

try {
  Console.WriteLine(carMap["Tom"]);
  
  carMap.Remove("Tom");
  Console.WriteLine(carMap["Tom"]);
} catch{
  Console.WriteLine("Key not found!");
}

Sets

using System.Collections.Generic;

HashSet<string> cars = new HashSet<string>();

cars.Add("Mazda");
cars.Add("Toyota");
cars.Add("Honda");

Console.WriteLine(cars.Contains("Honda") + "\n");

cars.Remove("Honda");
Console.WriteLine(cars.Contains("Honda"));

Stack

using System.Collections.Generic;

Stack<string> cars = new Stack<string>();

cars.Push("Mazda");
cars.Push("Toyota");
cars.Push("Honda");
Console.WriteLine(
  cars.Contains("Honda") + "\n"
);

cars.Pop();
Console.WriteLine(
  cars.Contains("Honda")
);

Queues

using System.Collections.Generic;

Queue<string> cars = 
  new Queue<string>();

cars.Enqueue("Mazda");
cars.Enqueue("Toyota");
cars.Enqueue("Honda");
Console.WriteLine(
  cars.Contains("Mazda") + "\n"
);

cars.Dequeue();
Console.WriteLine(
  cars.Contains("Mazda")
);

Linked List

using System;
using System.Collections.Generic;

public class Node {
  public string value;
  public Node next;
  public Node(string Value) {
    value = Value;
  }
}

public class LinkedList {
  public Node head = null;
  
  public void addValue(string val) {
    Node newNode = new Node(val);
    if (head == null) {
      head = newNode;
    } else {
      Node current = head;
      while(current.next != null) {
        current = current.next;
      }
      current.next = newNode;
    }
  }
  public string returnHead() {
    return head.value;
  }

  public void traverse() {
    Node current = head;
    while(current != null) {
      Console.WriteLine(current.value );
      current = current.next;
    }
  }
  public static void Main(string[] args) {
    LinkedList carList = new LinkedList();
    carList.addValue("Mazda");
    carList.addValue("Toyota");
    carList.addValue("Honda");
    
    Console.WriteLine(carList.returnHead());
    carList.traverse();
  }
}

Graphs

using System;
using System.Collections.Generic;

public class Graph {
  Dictionary<string, List<string>> graphMap =
  new Dictionary<string, List<string>>();
  
  public void addNode(string val) {
    List<string> tempList = new List<string>();
    graphMap.Add(val, tempList);
  }
  
 public void addVertices(
   string node1, string node2
 ) {
    List<string> tempArr = new List<string>();
    
    if(graphMap.ContainsKey(node1) == false) {
      graphMap.Add(node1, tempArr);
    }
    if(graphMap.ContainsKey(node2) == false) {
      graphMap.Add(node2, tempArr);
    }

    graphMap[node1].Add(node2);
    graphMap[node2].Add(node1);
  }

  public void breadthTraverse(string start) {
    Queue<string> queue = new Queue<string>();
    queue.Enqueue(start);
    
    Dictionary<string, bool> visited = 
      new Dictionary<string, bool>();
      
    visited.Add(start, true);
    
    while(queue.Count > 0) {
      string val = queue.Dequeue();
      Console.WriteLine(val + "\n");

      List<string> tempArr = graphMap[val];

      for (int i = 0; i < tempArr.Count; i++) {
        string tempKey = tempArr[i];
        if(
          visited.ContainsKey(tempKey) == false
        ) {
           queue.Enqueue(tempKey);
           visited.Add(tempKey, true);
        }
      }
    }
  }

  public void depthTraverse(string start) {
    Stack<string> stack = new Stack<string>();
    stack.Push(start);

    Dictionary<string, bool> visited = 
      new Dictionary<string, bool>();
      
    visited.Add(start, true);
    
    while(stack.Count > 0) {
      string val = stack.Pop();
      Console.WriteLine(val + "\n");

      List<string> tempArr = graphMap[val];

      for (int i = 0; i < tempArr.Count; i++) {
        string tempKey = tempArr[i];
        if(
          visited.ContainsKey(tempKey) == false
        ) {
          stack.Push(tempKey);
          visited.Add(tempKey, true);
        }
      }
    }
  }
 
  public static void Main(string[] args) {
    Graph newGraph = new Graph();
    newGraph.addNode("a");
    newGraph.addVertices("a", "b");
    newGraph.addVertices("a", "c");
    newGraph.addVertices("b", "d");
    newGraph.addVertices("b", "e");
    newGraph.addVertices("d", "f");
    newGraph.addVertices("d", "g");
    newGraph.addVertices("d", "h");
    newGraph.addVertices("e", "i");
    newGraph.addVertices("e", "j");
    newGraph.breadthTraverse("a");
    newGraph.depthTraverse("a");
  }
}

For Loops

using System.Collections.Generic;

List<string> names = new List<string>();
names.Add("Joe");
names.Add("Alex");
names.Add("Bob");
  
for (int i = 0; i < names.Count; i++) {
  Console.WriteLine(names[i]);
}

While Loops

using System.Collections.Generic;

List<string> carList = new List<string>();
carList.Add("Mazda");
carList.Add("Toyota");
carList.Add("Honda");
        
while(carList.Count > 0) {
  Console.WriteLine(carList[0] + "\n");
  carList.RemoveAt(0);
}

Console.WriteLine(carList.Count);

Loop Breaks

using System.Collections.Generic;

List<string> cars = new List<string>();
cars.Add("Toyota");
cars.Add("Honda");
cars.Add("Mazda");

for (int i = 0; i < cars.Count; i++) {
  if (cars[i] == "Honda") {
    Console.WriteLine("Found at index " + i + "\n");
    break;
  }
  Console.WriteLine("Visited index " + i + "\n");
}

Recursion

using System.Collections.Generic;

int getSum(List<int> arr) {

  if (arr.Count == 0) return 0;
  int firstVal = arr[0];
  arr.RemoveAt(0);
  Console.WriteLine(firstVal +"\n");
  
  return firstVal + getSum(arr);
}

List<int> testArr = new List<int>();
testArr.Add(1);
testArr.Add(2);
testArr.Add(4);
testArr.Add(5);

int sum = getSum(testArr);
Console.WriteLine(sum);

Regex Words

using System.Text.RegularExpressions;

string pattern = @"\w*";
Regex rg = new Regex(pattern);

string phrase = "I am legend";
match match = rg.match(phrase);

Console.WriteLine(match);

Regex Numbers

using System.Text.RegularExpressions;

string pattern = @"[0-9]+";
Regex rg = new Regex(pattern);

string phrase = "I am 23";
match match = rg.match(phrase);

Console.WriteLine(match);

Regex Test

using System.Text.RegularExpressions;

string pattern = @"Lee";
Regex rg = new Regex(pattern);

string phrase = "Bob Lee";
bool match = rg.IsMatch(phrase);

Console.WriteLine(match);

Regex Characters

using System.Text.RegularExpressions;

string pattern = @"\W*\w*";
Regex rg = new Regex(pattern);

string phrase = "##I am legend##";
match match = rg.match(phrase);

Console.WriteLine(match);

IronCodeMan

Basics

Data Structure

Iterables

Classes

Regex

Concepts for C#

Print Text

Comments

Variables

Data Types

Math Op

Math Functions

If/Else

Ternary

Switch

Functions

Interpolation

Type Casting

Date and Time

Classes

Inheritance

Method Overload

Abstract Class

Static Class

Arrays/Lists

Array Methods

Concatenation

Sort Method

Objects

Maps (Key/Value)

Sets

Stack

Queues

Linked List

Graphs

For Loops

While Loops

Loop Breaks

Recursion

Regex Words

Regex Numbers

Regex Test

Regex Characters