static void Main()
{
const int numberOfIntegers = 10, numberOfPeople = 10;
int[] integers = IntegerList.CreateRandomIntegers(numberOfIntegers, -50, 50);
Console.Write("Integers: [");
integers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * Square values
var squareValues = integers.Select(integer => integer * integer);
Console.Write("\nSquare values: [");
squareValues.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * Summation
int summation = 0;
var summations = integers.Select(integer => {
summation += integer;
return(summation);
});
Console.Write("\nSummations: [");
summations.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
Person[] people = PersonList.CreateRandomPeople(numberOfPeople);
Console.WriteLine("\nPeople:");
people.ForEach(Console.WriteLine);
// * All of them are one year older
var grownUp = people.Select(person => person.Birthday());
Console.WriteLine("\nPeople a year older:");
grownUp.ForEach(Console.WriteLine);
// * We take the people's ages
var ages = people.Select(person => person.Age);
Console.Write("\nAges: [");
ages.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * People's incomes
IDictionary <string, decimal> incomePerIdNumber = PersonList.CreateRandomIncomePerPerson(people);
var incomes = people.Select(person => incomePerIdNumber[person.IDNumber]);
Console.Write("\nIncomes: [");
incomes.ForEach(Console.Write, income => Console.Write(", "));
Console.WriteLine("]");
}
static void Main()
{
const int numberOfIntegers = 10, numberOfPeople = 10;
int[] integers = IntegerList.CreateRandomIntegers(numberOfIntegers, -50, 50);
Console.Write("Integers: [");
integers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * Summation and arithmetic mean
int summation = integers.Aggregate((e1, e2) => e1 + e2);
Console.WriteLine("Summation: {0}\nAritmetic mean: {1}",
summation, summation / (double)numberOfIntegers);
// * An initial value (seed) can be passed
int zero = integers.Aggregate(-summation, (e1, e2) => e1 + e2);
Console.WriteLine("-Summation + Summation: {0}", zero);
// * When performing subtraction, we have to be careful, because
// the - operator is not associative => (1 - 2) - 1 = -2 <> 1 - (2 - 1) = 0
// * Therefore, the iteration order matters (left to right <> right to left)
// * From left to right
int leftToRight = integers.Aggregate((e1, e2) => e1 - e2);
Console.WriteLine("Left to right subtraction: {0}", leftToRight);
// * Right to left:
int rightToLeft = integers.Reverse().Aggregate((e1, e2) => e1 - e2);
Console.WriteLine("Right to left subtraction: {0}", rightToLeft);
// * We compute the average income
Person[] people = PersonList.CreateRandomPeople(numberOfPeople);
IDictionary <string, decimal> incomePerIdNumber = PersonList.CreateRandomIncomePerPerson(people);
var incomeSummation = people
.Select(person => incomePerIdNumber[person.IDNumber])
.Aggregate((income1, income2) => income1 + income2);
Console.WriteLine("Average income: {0:N} euros.", incomeSummation / people.Length);
}
static void Main()
{
const int numberOfIntegers = 100, numberOfPeople = 30;
int[] integers = IntegerList.CreateRandomIntegers(numberOfIntegers);
Person[] people = PersonList.CreateRandomPeople(numberOfPeople);
Console.Write("Integers: [");
integers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
Console.WriteLine("\nPeople:");
people.ForEach(Console.WriteLine);
// * Example use of Filter (Where in Linq)
// * Even numbers
var evenNumbers = integers.Where(integer => integer % 2 == 0);
Console.Write("\nEven numbers: [");
evenNumbers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * Positive odd numbers
var positiveOddNumbers = integers.Where(integer => integer % 2 != 0 && integer > 0);
Console.Write("\nPositive odd numbers: [");
positiveOddNumbers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * People 18 and beyond
var beyond18 = people.Where(person => person.Age >= 18);
Console.WriteLine("\nPeople 18 and beyond:");
beyond18.ForEach(Console.WriteLine);
// * People with a specific name
Random random = new Random();
string name = PersonList.FirstNames[random.Next(PersonList.FirstNames.Length)];
var peopleSpecificName = people.Where(person => person.FirstName.Equals(name));
Console.WriteLine("\nPeople named \"{0}\":", name);
peopleSpecificName.ForEach(Console.WriteLine);
// * A new list of integers
integers = IntegerList.CreateRandomIntegers(numberOfIntegers, -50, 50);
Console.Write("Integers: [");
integers.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
// * Computes the set of duplicated numbers (only one ocurrence per duplicated number)
// * processed stores the integers that were processed
// * duplicated stores the integers that were already detected as duplicated
// * setOfDuplicated is like duplictated, but a set (a single occurrence per number)
IList <int> processed = new List <int>(), duplicated = new List <int>();
var setOfDuplicated = integers.Where(
integer => {
if (processed.Contains(integer))
{
if (duplicated.Contains(integer))
{
return(false); // Already included in duplicated
}
duplicated.Add(integer);
return(true); // It is a duplicated number
}
processed.Add(integer);
return(false); // It is not duplicated (by now)
}
);
Console.Write("\nDuplicated values: [");
setOfDuplicated.ForEach(Console.Write, integer => Console.Write(", "));
Console.WriteLine("]");
}
