using System.Data;

namespace CsCodeExample;

class Program

{

static void Main(string[] args)

{

// - LINE COMMENT

/*

SEGMENT COMMENT

*/

// break point(F5, F10), refactor, search and replace, Go to def., Find all ref., (un)comment

#region MyRegion

// your collapsible code here

#endregion

#region Output

Console.Write("OUTPUT:");

Console.WriteLine("Program is running.");

Console.WriteLine();

#endregion

#region Variables

// VARIABLES (local - must be assigned)

// primitive(built in) type / object (value range)

/*

bool / Boolean (true, false) [default: false]

byte / Int8 (+- 127) [default: 0]

short / Int16 (+- 32,767) [default: 0]

int / Int32 (+- 2,147,483,647) [default: 0]

long / Int64 (+- 9,223,372,036,854,775,807) [default: 0]

float (+- 1.5 E−45 to +- 3.40282347 E+38) [default: 0] Precision: ~6-9 digits

double (+- 5.0 E−324 to +- 1.7976931348623157 E+308) [default: 0] Precision: ~15-17 digits

decimal / Decimal (+- 1.0 E-28 to +- 7.9228 E28) [default: 0] Precision: 28-29 digits

char / Char [default: '']

string / String [default: null, nullable]

var // can be any type

*/

#endregion

#region Naming Conventions

/*

local variables - nonCapitalLetter, camelCase

Class, Function(Method - in a class) and Property name - CapitalLetter, PascalCase

DO choose easily readable identifier names(exmample HorizontalAlignment more English-readable than AlignmentHorizontal)

DO favor readability over brevity.

The property name CanScrollHorizontally is better than ScrollableX (an obscure reference to the X-axis).

DO NOT use underscores(Hungarian notation), hyphens, or any other nonalphanumeric characters.

AVOID using identifiers that conflict with keywords of widely used programming languages.

*/

#endregion

#region Declaration

// Declaration of variable (camelCase Notation)

bool isAdmin;

int counter;

double sum;

decimal number;

char character;

string name;

// Assignment of variable

isAdmin = true;

counter = 5;

sum = 3.14;

number = 18.65m;

character = 'a';

name = "Ben Benito";

Console.WriteLine("c" + counter);

// Declaration and Assignment

bool isActive = true;

// Nullable (can take all values of its underlying value type and an additional null value)

bool? isEnded = null;

string city = null;

// String is null (and therefore nullable) by default, so there's no need for this notation)

// Cast

int inputAmount = 126;

decimal secondAmount = inputAmount; // implicit cast

int thirdAmount = (int)secondAmount; // explicit cast

string strNum = "1234";

int outputNum = int.Parse(strNum);

Console.WriteLine("DECLARATION");

Console.WriteLine("T or F: " + isAdmin);

Console.WriteLine("Counter: " + counter);

Console.WriteLine("Sum: " + sum);

Console.WriteLine("Number: " + number);

Console.WriteLine("Letter: " + character);

Console.WriteLine("Word or Sentance: " + name);

Console.WriteLine("Active: " + isActive);

Console.WriteLine("Finished: " + isEnded);

// string interpolation

Console.WriteLine("City Name: " + city); // Old way to concatenate strings

Console.WriteLine("City Name: {0}", city);

Console.WriteLine($"City Name: {city}"); // Newest way, from C# 6 version

Console.WriteLine();

#endregion

#region Operators

// Arithmetic Operators

// = + - * / %

int x = 10, y = 6; // Declaration and assignment of multiple variables of the same type at once

int result = x + y;

Console.WriteLine("OPERATORS");

Console.WriteLine("a + b = " + x + " + " + y + " = " + result);

Console.WriteLine("a + b = {0} + {1} = {2}", x, y, result);

Console.WriteLine($"a + b = {x} + {y} = {result}");

x *= 2;

//x = x * 2;

x++;

//x = x + 1;

//x--;

//x = x - 1;

Console.WriteLine("x = x * 2 + 1 = " + x);

Console.WriteLine("r = x++ = " + x++); // output is the value of x BEFORE incrementing

Console.WriteLine("x= " + x);

Console.WriteLine("r = ++x = " + ++x); // output is the value of x AFTER incrementing

Console.WriteLine("x = " + x);

Console.WriteLine("");

// Relation Operators

// == != > >= < <=

// Logical Operators

// && AND

// || OR

// ! NOT

#endregion

#region Selection Statements (Conditionals)

Console.WriteLine("SELECTION STATEMENTS (Conditionals)");

// if, else, switch, case

bool print = true;

if (print)

Console.WriteLine("true - ");

print = false;

if (print)

Console.WriteLine("false - no output");

if (!print)

Console.WriteLine("not false = true - output");

int age = 20;

if (age > 18)

Console.WriteLine("Adult");

else

Console.WriteLine("Minor");

int value = 23; // value range 0-29

string clause = "Value is from-to: ";

if (value >= 0 && value < 10)

Console.WriteLine(clause + "0-9");

else if (value >= 10 && value < 20)

Console.WriteLine(clause + "10-19");

else if (value >= 20 && value < 30)

Console.WriteLine(clause + "20-29");

else

Console.WriteLine(clause + "30+");

int mod = value % 3;

if (mod == 1)

Console.WriteLine("Remainder 1");

else if (mod == 2)

Console.WriteLine("Remainder 2");

else

Console.WriteLine("Divisible with 3");

switch (mod)

{

case 1:

Console.WriteLine("Remainder 1");

break;

case 2:

Console.WriteLine("Remainder 2");

break;

default:

Console.WriteLine("Divisible with 3");

break;

}

int? year = null;

// null coalescing operator (??) - returns the value of its left-hand operand if it isn't null; otherwise, it evaluates the right-hand operand and returns its result

Console.WriteLine("Year = " + (year ?? 2017)); // returns 2017, as year == null

string yearType = year % 2 == 0 ? "Even year" : "Odd year"; // (? :) - conditional operator, ternary

// General case: result = condition ? result if condition is true : result if condition is false;

Console.WriteLine("Year type :" + yearType);

#endregion

#region Iteration Statements

Console.WriteLine("ITERATION STATEMENTS");

// for, while, do, foreach, in

// Jump statements

// break, continue, default, return, (go to)

// Exception handling statements

// throw, try-catch

Console.Write("For loop: ");

for (int i = 1; i <= 5; i++)

Console.Write(i + " ");

Console.WriteLine("");

Console.Write("While a): ");

// Do - while loop, executes at least once, even if the condition is not fulfilled

int k = 40;

do

{

k = k * 2;

Console.Write(k + " ");

} while (k < 20);

Console.WriteLine("");

Console.Write("While b): ");

k = 1;

while (k < 20)

{

k = k * 2;

if (k == 8)

break;

Console.Write(k + " ");

}

Console.WriteLine("");

Console.Write("While c): ");

k = 1;

while (k < 20)

{

k = k * 2;

if (k == 8)

continue;

Console.Write(k + " ");

}

Console.Write("\n\n");

#endregion

#region Arrays

Console.WriteLine("ARRAYS");

double[] fiveDayPrices = new double[5]; // fixed size;

fiveDayPrices[0] = 3.45;

fiveDayPrices[1] = 3.55;

fiveDayPrices[2] = 3.58;

fiveDayPrices[3] = 3.30;

fiveDayPrices[4] = 3.32;

Console.Write("Five day prices: ");

for (int i = 0; i < 5; i++)

{

Console.Write(fiveDayPrices[i] + " ");

}

Console.Write("\nFive day prices backwards: ");

for (int i = fiveDayPrices.Length - 1; i >= 0; i--)

{

Console.Write(fiveDayPrices[i] + " ");

}

Console.Write("\nForeach: ");

foreach (var element in fiveDayPrices)

{

Console.Write(element + " ");

}

Console.WriteLine("");

Console.WriteLine("Matrix");

// Multidimensional arrays

// Two-dimensional array.

int[,] matrix = new int[3, 3]; // fixed size;

matrix[0, 0] = 1;

matrix[0, 1] = 2;

matrix[0, 2] = 3;

matrix[1, 0] = 4;

matrix[1, 1] = 5;

matrix[1, 2] = 6;

matrix[2, 0] = 7;

matrix[2, 1] = 8;

matrix[2, 2] = 9;

for (int i = 0; i < 3; i++)

for (int j = 0; j < 3; j++)

Console.Write(matrix[i, j] + " ");

Console.WriteLine();

int[,] matrixB = new int[3, 3]; // fixed size;

for (int i = 0; i < 3; i++)

{

for (int j = 0; j < 3; j++)

{

matrixB[i, j] = (i * 3) + j + 1;

Console.Write(matrixB[i, j] + " ");

if ((j + 1) % 3 == 0)

Console.WriteLine("");

}

}

// A similar array with string elements.

string[,] array2Db = new string[3, 2] { { "one", "two" }, { "three", "four" }, { "five", "six" } };

// Three-dimensional array.

int[,,] array3D = new int[,,] { { { 1, 2, 3 }, { 4, 5, 6 } }, { { 7, 8, 9 }, { 10, 11, 12 } } };

Console.WriteLine("Dif. Matrix");

// Array(Jagged) that can have different row size

// This could be clarified!

int[][] jaggedArray = new int[3][];

for (int i = 0; i < 3; i++)

{

jaggedArray[i] = new int[(i + 1)];

for (int j = 0; j < (i + 1); j++)

{

jaggedArray[i] = new int[(i + 1)];

jaggedArray[i][j] = (i * 3) + j + 1;

Console.Write(jaggedArray[i][j] + " ");

if ((j + 1) % (i + 1) == 0)

Console.WriteLine("");

}

}

// List

List<string> words = new List<string>

{

"one",

"two",

"three",

};

words.Add("four");

words.Add("five");

words.Remove("three");

Console.WriteLine("");

foreach (var word in words)

Console.Write(word + " ");

Console.WriteLine("\n" + words[1]);

Console.WriteLine(words.ElementAt(1));

List<char> letters = new List<char>() { 'a', 'b', 'c' };

foreach (var letter in letters)

{

Console.Write(letter + " ");

}

// Dictionary

Dictionary<String, int> accounts = new Dictionary<String, int>

{

{ "Cash", 110 },

{ "Receivable", 120 },

{ "Supplies", 130 },

};

accounts.Add("Insurance", 150);

accounts.TryGetValue("Supplies", out int account);

Console.Write("\nSupplies account: " + account);

List<string> sentences = new List<string>

{

"I am playing",

"I play",

"You are going",

"You go",

"He is running"

};

sentences.Remove("He runs");

// Lambda expression =>

IEnumerable<string> ingEndSentences = sentences.Where(a => a.EndsWith("ing")); // EndsWith, Contains

List<string> ingEndSentences2 = sentences.Where(a => a.EndsWith("ing")).ToList(); // EndsWith, Contains

Console.WriteLine("\nING:");

foreach (var sentence in ingEndSentences2)

{

Console.WriteLine(sentence);

}

List<string> ingEndSentences3 = new List<string>();

foreach (var sentence in sentences)

{

if (sentence.EndsWith("ing"))

{

ingEndSentences3.Add(sentence);

}

}

#endregion

#region Parsing and Exceptions

Console.WriteLine("\n\nPARSING AND EXCEPTIONS");

string customNumStr = "324erer";

int customNum;

var validNum = int.TryParse(customNumStr, out customNum);

if (validNum)

Console.WriteLine(customNum);

else

Console.WriteLine("Parse Error");

try

{

customNum = Int32.Parse(customNumStr);

}

catch (Exception ex)

{

Console.WriteLine("Exception:\n" + ex.StackTrace + "\n");

//throw new Exception("Exception on Parsing string to int.");

}

#endregion

#region Methods

Console.WriteLine("\nMETHODS (Functions)");

// Access Modifiers

// public - most accessible

// protected - in class where declared and all derived classes

// internal - within files in the same assembly

// private - only in class where declared

// Output: return type(one) - [void = no return], side effects

// Input: arguments

// keyword static - can be called without object instantiation

PrintText("To be printed.");

PrintText("End.");

decimal num1 = 12.3m;

decimal num2 = 2.5m;

int num3 = 3;

decimal quotient = Divide(num1, num2); // num1, num2 are Arguments - values on function call

Console.WriteLine("{0} / {1} = {2}", num1, num2, quotient);

Console.WriteLine("{0} * {1} * {2} = {3}", num1, num2, num3, Multiple(num1, num2, num3));

Console.WriteLine("{0} * {1} = {2}", num1, num2, Multiple(num1, num2));

Console.WriteLine("{0} * {0} = {1}", num1, Multiple(num1));

Console.WriteLine("5! = " + Fact(5)); //Recursion

Console.WriteLine("6! = " + Factorial(6));

Console.WriteLine("Log10(136) = " + Math.Log10(136));

#endregion

#region Enum

Console.WriteLine("\nENUM"); // Enumerator

Gender wordGender = Gender.Neutrum;

Gender word2Gender = (Gender)1; // cast

Console.WriteLine("word Gender: " + wordGender);

Console.WriteLine("word2 Gender: " + word2Gender);

if (wordGender == Gender.Neutrum)

{

Console.WriteLine("word Gender: " + wordGender.ToString());

Console.WriteLine("word Gender Id: " + (int)wordGender);

}

Sex personSex = Sex.Male;

Console.WriteLine("Sex: " + personSex.ToString());

Console.WriteLine("Sex: " + personSex.GetDescription());

Console.WriteLine("All Genders:");

foreach (Gender gender in Enum.GetValues(typeof(Gender)))

{

Console.WriteLine("- {0}", gender.GetDescription());

}

#endregion

#region Classes

Console.WriteLine("\nCLASSES");

decimal xReal = 2, xImag = 3;

decimal yReal = 4, yImag = 5;

decimal zReal, zImag;

zReal = Add(xReal, yReal);

zImag = Add(xImag, yImag);

ComplexNumber xComplex = new ComplexNumber(2, 3);

ComplexNumber yComplex = new ComplexNumber(4, 5);

ComplexNumber zComplex = xComplex.Add(yComplex);

// System Class

DateTime currentDate = DateTime.Now;

Console.WriteLine("DateTime.Now() = {0}", currentDate);

Console.WriteLine("Date = {0} ", currentDate.ToString("dd.MM.yyyy"));

Console.WriteLine("Date = {0:dd.MM.yyyy} ", currentDate);

Console.WriteLine("Year = " + currentDate.Year);

// Custom Classes

// ComplexNumber

Console.WriteLine("");

Console.WriteLine(ComplexNumber.Format);

Console.WriteLine(ComplexNumber.GetDescription());

ComplexNumber complex0 = new ComplexNumber();

complex0.Real = 1;

ComplexNumber complex1 = new ComplexNumber(5, 3);

double r = complex1.Real;

ComplexNumber complex2 = new ComplexNumber

{

Real = 6,

Imag = 7

};

ComplexNumber complex3;

complex3 = new ComplexNumber()

{

Real = 4,

Imag = 2

};

MoreComplexNumber complex4 = new MoreComplexNumber(4, 2);

MoreComplexNumber complex = new MoreComplexNumber();

ComplexNumber summation = complex1.Add(complex2).Add(complex3);

//ComplexNumber summation2 = ComplexNumber.Add(ComplexNumber.Add(complex1, complex2), complex3);

ComplexNumber division = complex1.Divide(complex2);

Console.WriteLine("c0 = " + complex0);

Console.WriteLine("c1 = " + complex1);

Console.WriteLine("c2 = " + complex2.ToString());

Console.WriteLine("c3 = " + complex3.ToDiffString());

Console.WriteLine("c4 = " + complex4.ToDiffString());

Console.WriteLine("\nsummation = " + summation.ToDiffString());

Console.WriteLine("division = " + division.ToDiffString());

Console.WriteLine("minus = " + new ComplexNumber(2, -5).ToDiffString());

Console.WriteLine("real = " + new ComplexNumber(7, 0).ToDiffString());

Console.WriteLine("c1(modul) = " + complex1.Modul());

Console.WriteLine("c1 ^ 0 =" + complex1.Pow(0));

Console.WriteLine("c1 ^ 1 =" + complex1.Pow(1));

Console.WriteLine("c1 ^ 2 =" + complex1.Pow(2));

Console.WriteLine("c1 ^ 4 =" + complex1.Pow(2));

Console.WriteLine("c1 ^ (-2) =" + complex1.Pow(-2));

List<ComplexNumber> roots = complex1.Nroot(3);

Console.WriteLine("c1 ^ (1/3) = ");

foreach (var c in roots)

Console.WriteLine(c);

// User

User user = new User()

{

FirstName = "John",

LastName = "Reacher",

PersonSex = Sex.Male,

BirthDate = DateTime.Parse("12/5/1987"),

UserName = "Johnny",

Email = "joe@gmail.com",

Company = "Google",

YearsOfService = 5,

Sallary = 2000/*,

HomeAddress = new Address()

{

City = "Banjaluka",

Street = "Jevrejska"

}*/

};

user.ResetPassword("1234abc!");

user.HomeAddress = new Address()

{

City = "London",

Street = "Baker Street"

};

Console.WriteLine("\nUSER: " + user);

Console.WriteLine("Year of Birth: " + user.BirthDate.Year);

Console.WriteLine("City: " + user.HomeAddress.City);

Square Square = new Square(4);

Console.WriteLine("Square(side:4), area = " + Square.CalcArea());

#endregion

#region InputConsole

Console.WriteLine("INPUT (console)");

string input = null;

while (input != "")

{

Console.Write("\nInput number:");

input = Console.ReadLine();

bool inputValid = int.TryParse(input, out int inputNum);

if (inputValid)

Console.WriteLine("Number is valid. (Press Enter to Finish)\n");

else

Console.WriteLine("Number is not valid.(Press Enter to Finish)\n");

}

#endregion

#region InputFile

Console.WriteLine("INPUT (file)");

Console.Write("\nInput file path(Enter for no file, 'd' for default[ComplexIn.csv]): ");

string desktop_path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "//";

string filePath = null;

string inputFilePath = Console.ReadLine();

if (inputFilePath == "d")

inputFilePath = "ComplexIn.csv";

if (inputFilePath != "")

filePath = desktop_path + inputFilePath;

string output_file = "ComplexOut.csv";

string line = null;

char separator = ',';

List<ComplexNumber> complexNumbers = new List<ComplexNumber>();

if (inputFilePath != "")

using (StreamReader str_reader = new StreamReader(filePath))

{

str_reader.ReadLine(); // skips first line as it contains names of columns

while ((line = str_reader.ReadLine()) != null)

{

string[] values = line.Split(separator);

complexNumbers.Add(new ComplexNumber(Double.Parse(values[0]), Double.Parse(values[1])));

}

//output all objects to the file

string output_path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);

using (StreamWriter wr = new StreamWriter(desktop_path + output_file))

{

wr.WriteLine("Real,Imag");

foreach (var complexNumber in complexNumbers)

wr.WriteLine(complexNumber.ToCSV());

}

}

Console.WriteLine("Press Enter for Quit.");

Console.ReadKey();

// Don't copy code, all that is repeated should be in functions

}

#endregion

public static decimal Add(decimal xRealOrImag, decimal yRealOrImag)

{

decimal zRealOrImag = xRealOrImag + yRealOrImag;

return zRealOrImag;

}

public static string[] ConvertToStringArray(System.Array values)

{

string[] theArray = new string[values.Length];

for (int i = 1; i <= values.Length; i++)

{

if (values.GetValue(1, i) == null)

theArray[i - 1] = "";

else

theArray[i - 1] = (string)values.GetValue(1, i).ToString();

}

return theArray;

}

public static void PrintText(string input) // Name Convention: PascalCase Notation

{

Console.WriteLine(input);

}

public static decimal Divide(decimal dividend, decimal divisor)

{

return dividend / divisor;

// decimal result = dividend / divisor;

// return result;

} // dividend and divisor are Parameters, refer to names

public static decimal Multiple(decimal m1, decimal m2, decimal m3 = 1) // optional parameters

{

return m1 * m2 * m3;

}

public static decimal Multiple(decimal m1) // Function Overloading - same function name, different number of arguments (or type)

{

return m1 * m1;

}

// Recursion

public static int Fact(int n)

{

if (n <= 1)

return 1;

return n * Fact(n - 1);

}

///<summary>

///Calculates factorial of given number

///</summary>

public static int Factorial(int n)

{

if (n <= 1)

return 1;

int result = 1;

for (int i = 2; i <= n; i++)

{

result *= i;

}

return result;

}

}