Data Types and Variables

Data Types And Variables

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace DataTypesAndVariables

{

classProgram

{

staticvoid Main(string[] args)

{

Console.WriteLine("A: Variable Lifetime");

Console.WriteLine("B: Minimum and Maximum Values");

Console.WriteLine("C: Formatting With ToString");

Console.WriteLine("D: Decimal Literals");

Console.WriteLine("E: Decimal Data Type");

Console.WriteLine("F: Char Data Type");

Console.WriteLine("G: String Data Type");

Console.WriteLine("H: Boolean Data Type");

Console.WriteLine("I: Widening Conversions");

Console.WriteLine("");

Console.WriteLine("Enter an option <X to exit>:");

string s = Console.ReadLine();

switch (s)

{

case"A":

ShowTotalAmount();

break;

case"B":

MinMaxValues();

break;

case"C":

FormattingWithToString();

break;

case"D":

DecimalLiterals();

break;

case"E":

DecimalDataType();

break;

case"F":

CharDataType();

break;

case"G":

StringDataType();

break;

case"H":

BooleanDataType();

break;

case"I":

WideningConversions();

break;

case"J":

ImplicitExplicitConversions();

break;

default:

Console.WriteLine("Invalid selection. Please select from one of the above.");

break;

}

Console.ReadLine();

}

staticvoid VariableLifetime()

{

int totalAmount = 100;

totalAmount = totalAmount + 100;

}

staticint totalAmount; //This variable is declared at class level

staticvoid VariableScope()

{

totalAmount = 100;

ShowTotalAmount();

}

staticvoid ShowTotalAmount()

{

Console.WriteLine("Total amount is {0}", totalAmount);

}

staticvoid MinMaxValues()

{

//Integer data types

Console.WriteLine("A byte variable can be between {0} and {1}", byte.MinValue, byte.MaxValue);

Console.WriteLine("A sbyte variable can be between {0} and {1}", sbyte.MinValue, sbyte.MaxValue);

Console.WriteLine("A short variable can be between {0} and {1}", short.MinValue, short.MaxValue);

Console.WriteLine("A ushort variable can be between {0} and {1}", ushort.MinValue, ushort.MaxValue);

Console.WriteLine("A int variable can be between {0} and {1}", int.MinValue, int.MaxValue);

Console.WriteLine("A uint variable can be between {0} and {1}", uint.MinValue, uint.MaxValue);

Console.WriteLine("A long variable can be between {0} and {1}", long.MinValue, long.MaxValue);

Console.WriteLine("A ulong variable can be between {0} and {1}", ulong.MinValue, ulong.MaxValue);

//Floating point data types

Console.WriteLine("A single variable can be between {0} and {1}", Single.MinValue, Single.MaxValue);

Console.WriteLine("A double variable can be between {0} and {1}", Double.MinValue, Double.MaxValue);

Console.WriteLine();

//Decimal point data types

Console.WriteLine("A decimal variable can be between {0} and {1}", Decimal.MinValue, Decimal.MaxValue);

Console.WriteLine();

//DateTime data types

Console.WriteLine("A DateTime variable can be between {0} and {1}", DateTime.MinValue, DateTime.MaxValue);

}

staticvoid FormattingWithToString()

{

int totalAmount = 1000;

Console.WriteLine("The value of intVariable is " + totalAmount.ToString());

Console.WriteLine("intVariable in general format is " + totalAmount.ToString("g"));

Console.WriteLine("intVariable in decimal format is " + totalAmount.ToString("d"));

Console.WriteLine("intVariable in number format is " + totalAmount.ToString("n"));

Console.WriteLine("intVariable in currency format is " + totalAmount.ToString("c"));

Console.WriteLine("intVariable in hexadecimal format is " + totalAmount.ToString("x"));

}

staticvoid DecimalLiterals()

{

decimal totalAmount;

totalAmount = 45.61M; //M implicitly converts this value to a double

}

staticvoid DecimalDataType()

{

decimal totalAmount;

totalAmount = 45.61M;

decimal totalPounds, totalPence;

totalPounds = decimal.Truncate(totalAmount);

totalPence = totalAmount - totalPounds;

Console.WriteLine("The restaurant bill is {0:C}", totalAmount);

Console.WriteLine("You pay the {0:C} and I'll pay the {1:C}", totalPounds, totalPence);

Console.WriteLine();

totalAmount = 45.674586748657M;

Console.WriteLine("The total amount is {0}", totalAmount);

Console.WriteLine("Rounded to 0 decimal places, this value is {0}", Decimal.Round(totalAmount));

Console.WriteLine("Rounded to 4 decimal places, this value is {0}", Decimal.Round(totalAmount, 4));

Console.WriteLine();

totalAmount = -46.51M;

Console.WriteLine("Profit last month was {0}", totalAmount);

decimal totalPounds1;

decimal totalPounds2;

totalPounds1 = Decimal.Floor(totalAmount);

totalPounds2 = Decimal.Ceiling(totalAmount);

Console.WriteLine("Rounding down this number is {0}", totalPounds1);

Console.WriteLine("Rounding up this number is {0}", totalPounds2);

}

staticvoid CharDataType()

{

Console.WriteLine("Code point 82 is {0}", char.ConvertFromUtf32(82));

Console.WriteLine("The code point of R is {0}", char.ConvertToUtf32("R", 0));

Console.WriteLine();

char charVariable1 = 'A';

char charVariable2 = '7';

char charVariable3 = '+';

Console.WriteLine("A is a control character: {0}", char.IsControl(charVariable1));

Console.WriteLine("A is a digit: {0}", char.IsDigit(charVariable1));

Console.WriteLine("A is a letter: {0}", char.IsLetter(charVariable1));

Console.WriteLine("A is lowercase: {0}", char.IsLower(charVariable1));

Console.WriteLine("7 is a number: {0}", char.IsNumber(charVariable2));

Console.WriteLine("7 is punctuation: {0}", char.IsPunctuation(charVariable2));

Console.WriteLine("+ is a separator: {0}", char.IsSeparator(charVariable3));

Console.WriteLine("+ is white space: {0}", char.IsWhiteSpace(charVariable3));

}

staticvoid StringDataType()

{

string greeting1 = "Hello \"Robert\"";

string greeting2 = @"Hello ""Robert""";

Console.WriteLine(greeting1);

Console.WriteLine(greeting2);

Console.WriteLine();

Console.WriteLine("The file is on \\server\allcode."); // the \a is the code for a beep

Console.WriteLine("The file is on \\\\server\\allcode.");

Console.WriteLine(@"The file is on \\server\allcode.");

Console.WriteLine();

}

staticvoid BooleanDataType()

{

int firstVariable = 7;

int secondVariable = 6;

if (firstVariable > secondVariable)

{

Console.WriteLine("{0} is greater than {1}", firstVariable, secondVariable);

}

}

staticvoid ObjectDataType()

{

object anything;

anything = 65.57; //store a double

Console.WriteLine("{0} is {1}", anything, anything.GetType());

anything = "A";

Console.WriteLine("{0} is {1}", anything, anything.GetType());

}

staticvoid ImplicitExplicitConversions()

{

//Implicit conversion of an integer to a decimal

//int unitsOrdered = 100;

//decimal unitPrice = 24.1M;

//decimal totalAmount;

//totalAmount = unitsOrdered * unitPrice;

//Implicit conversion of an integer to a decimal will fail

int unitsOrdered = 100;

decimal unitPrice = 24.1M;

int totalAmount;

//totalAmount = unitsOrdered * unitPrice; //This will fail!

totalAmount = (int)(unitsOrdered * unitPrice);//We need to add int as an implicit cast

}

staticvoid WideningConversions()

{

ConversionOperators();

Console.WriteLine();

Console.WriteLine("Do the same with the Convert class");

Console.ReadKey();

//Use the Convert class

ConvertClass();

Console.WriteLine();

Console.WriteLine("Do the same with the Parse method");

Console.ReadKey();

//Use the Parse method

ParseMethod();

}

staticvoid ConversionOperators()

{

byte byteValue;

short shortValue;

int integerValue;

long longValue;

float floatValue;

double doubleValue;

decimal decimalValue;

char charValue;

string stringValue;

byteValue = 2;

shortValue = 100;

Console.WriteLine("byteValue is {0}, shortValue is {1}", byteValue, shortValue);

shortValue =(short)(shortValue + byteValue); // C# default is integer when adding two values together, so we need to cast as short

Console.WriteLine("Add them and shortValue is {0}", shortValue);

Console.WriteLine();

shortValue = 100;

integerValue = 1000;

Console.WriteLine("shortValue is {0}, integerValue is {1}", shortValue, integerValue);

integerValue = integerValue + (int)shortValue;

Console.WriteLine("Add them and the integer value is {0}", integerValue);

Console.WriteLine();

integerValue = 1000;

longValue = 3000000;

Console.WriteLine("integerValue is {0}, and longValue is {1}", integerValue, longValue);

longValue = longValue + (long)integerValue;

Console.WriteLine("Add them and the longValue is {0}", longValue);

Console.WriteLine();

longValue = 3000000;

floatValue = 2000.12341F;

Console.WriteLine("longValue is {0}, floatValue is {1}", longValue, floatValue);

floatValue = floatValue + (float)longValue;

Console.WriteLine("Add them and floatValue is {0}", floatValue);

Console.WriteLine();

floatValue = 2000.12341F;

doubleValue = 50000.1234;

Console.WriteLine("floatValue is {0}, and doubleValue is {1}", floatValue, doubleValue);

doubleValue = doubleValue + (double)floatValue;

Console.WriteLine("Add them and doubleValue is {0}", doubleValue);

Console.WriteLine();

doubleValue = 50000.1234;

decimalValue = 6000000.1234M;

Console.WriteLine("doubleValue is {0}, decimalValue is {1}", doubleValue, decimalValue);

decimalValue = decimalValue + (decimal)doubleValue;

Console.WriteLine("Add them and decimalValue is {0}", decimalValue);

Console.WriteLine();

decimalValue = 6000000.1234M;

stringValue = "ABC";

Console.WriteLine("decimalValue is {0}, stringValue is {1}", decimalValue, stringValue);

stringValue = stringValue + decimalValue.ToString();

Console.WriteLine("Add them together and stringValue is {0}", stringValue); //This will concatenate the two

Console.WriteLine();

charValue = 'A';

stringValue = "ABC";

Console.WriteLine("charValue is {0}, stringValue is {1}", charValue, stringValue);

stringValue = stringValue + charValue.ToString();

Console.WriteLine("Add them together and stringValue is {0}", stringValue);

Console.WriteLine();

}

staticvoid ConvertClass()

{

byte byteValue;

short shortValue;

int integerValue;

long longValue;

float floatValue;

double doubleValue;

decimal decimalValue;

byteValue = 2;

shortValue = 100;

Console.WriteLine("byteValue is {0}, shortValue is {1}", byteValue, shortValue);

shortValue =Convert.ToInt16(shortValue + byteValue);

Console.WriteLine("Add them and shortValue is {0}", shortValue);

Console.WriteLine();

shortValue = 100;

integerValue = 1000;

Console.WriteLine("shortValue is {0}, integerValue is {1}", shortValue, integerValue);

integerValue = integerValue + Convert.ToInt32(shortValue);

Console.WriteLine("Add them and the integer value is {0}", integerValue);

Console.WriteLine();

integerValue = 1000;

longValue = 3000000;

Console.WriteLine("integerValue is {0}, and longValue is {1}", integerValue, longValue);

longValue = longValue + Convert.ToInt32(integerValue);

Console.WriteLine("Add them and the longValue is {0}", longValue);

Console.WriteLine();

longValue = 3000000;

floatValue = 2000.12341F;

Console.WriteLine("longValue is {0}, floatValue is {1}", longValue, floatValue);

floatValue = floatValue + Convert.ToSingle(longValue);

Console.WriteLine("Add them and floatValue is {0}", floatValue);

Console.WriteLine();

floatValue = 2000.12341F;

doubleValue = 50000.1234;

Console.WriteLine("floatValue is {0}, and doubleValue is {1}", floatValue, doubleValue);

doubleValue = doubleValue + Convert.ToDouble(floatValue);

Console.WriteLine("Add them and doubleValue is {0}", doubleValue);

Console.WriteLine();

doubleValue = 50000.1234;

decimalValue = 6000000.1234M;

Console.WriteLine("doubleValue is {0}, decimalValue is {1}", doubleValue, decimalValue);

decimalValue = decimalValue + Convert.ToDecimal(doubleValue);

Console.WriteLine("Add them and decimalValue is {0}", decimalValue);

Console.WriteLine();

}

staticvoid ParseMethod()

{

byte byteValue;

short shortValue;

int integerValue;

long longValue;

float floatValue;

double doubleValue;

decimal decimalValue;

char charValue;

string stringValue;

byteValue = 2;

shortValue = (short)100; //Explicitly convert this up front. C# needs to understand that this is not an integer

Console.WriteLine("byteValue is {0}, shortValue is {1}", byteValue, shortValue);

shortValue = Int16.Parse((shortValue + byteValue).ToString());

Console.WriteLine("Add them and shortValue is {0}", shortValue);

Console.WriteLine();

shortValue = 100;

integerValue = 1000;

Console.WriteLine("shortValue is {0}, integerValue is {1}", shortValue, integerValue);

integerValue = integerValue + Int32.Parse(shortValue.ToString());

Console.WriteLine("Add them and the integer value is {0}", integerValue);

Console.WriteLine();

integerValue = 1000;

longValue = 3000000;

Console.WriteLine("integerValue is {0}, and longValue is {1}", integerValue, longValue);

longValue = longValue + Int64.Parse(integerValue.ToString());

Console.WriteLine("Add them and the longValue is {0}", longValue);

Console.WriteLine();

longValue = 3000000;

floatValue = 2000.12341F;

Console.WriteLine("longValue is {0}, floatValue is {1}", longValue, floatValue);

floatValue = floatValue + Single.Parse(longValue.ToString());

Console.WriteLine("Add them and floatValue is {0}", floatValue);

Console.WriteLine();

floatValue = 2000.12341F;

doubleValue = 50000.1234;

Console.WriteLine("floatValue is {0}, and doubleValue is {1}", floatValue, doubleValue);

doubleValue = doubleValue + Double.Parse(floatValue.ToString());

Console.WriteLine("Add them and doubleValue is {0}", doubleValue);

Console.WriteLine();

doubleValue = 50000.1234;

decimalValue = 6000000.1234M;

Console.WriteLine("doubleValue is {0}, decimalValue is {1}", doubleValue, decimalValue);

decimalValue = decimalValue + Decimal.Parse(doubleValue.ToString());

Console.WriteLine("Add them and decimalValue is {0}", decimalValue);

Console.WriteLine();

}

staticvoid ValueAndReferenceTypes()

{

}

}

}