static void Main(string[] args)
{
// LINQ languae INtegreted Query
int[] numbers = { 12, 323, 434, 53, 53, 545, 452345, 524, 542, 545325425 };
// method Syntax
var result = numbers.Where(num => num > 50).Select(num => num); // result datatype is INeumerable which is generic interface or datatypes
// Query syntax
var result2 = from num in numbers where num > 50 select num;
// Restriction - where
var results3 = from num in numbers where num > 50 && num < 60 select num;
// projections - select
var result4 = from num in numbers select num * num;
var result5 = from num in numbers where num % 2 == 0 select num * num;
// Ordering - order, order by descending
var result67 = from num in numbers orderby num descending select num;
// partitaioning : take method syntax not avaiable in query syntax
var result7 = numbers.Take(5);
var result8 = numbers.Skip(5).Take(5);
// quantifier
var result9 = numbers.Any(num => num % 2 == 0); // returns ture or false
var result10 = numbers.All(num => num % 2 == 0); // return false
var result11 = numbers.Contains(23);
// Generations
var result12 = Enumerable.Range(1, 1100);
var result123 = Enumerable.Repeat("hello World", 20); // to repeat same code for certain time
void LearnLinqComplexCollection()
{
Country c1 = new Country("Nepal", "kathmandu", 1234434, "Asia");
// countries.Add(c1); // adding the object c1 in List(countries) of object
Country c2 = new Country("india", "Delhi", 232132132323213, "asia", DateTime.Parse("1947/11/1"));
Country c3 = new Country("England", "London", 232132323213, "Europe");
Country c4 = new Country("Bhutan", "Dhaka", 132323213, "asia");
Country c5 = new Country("Australia", "Sydeny", 232133563213, "austrealia");
Country c6 = new Country("Russia", "Moscow", 2321324544523453213, "Europe");
Country c7 = new Country("America", "Wasington D C", 23213332132323213, "North America");
List <Country> countries = new List <Country> {
c1, c2, c3, c4, c5, c7
}; // creating the list of object by using generic method
// list of the asian country
var result = from c in countries
where c.Continent == "asia"
select c.Name;
// list all asian country name which are neer been invaded
// var result1 = from c in countries
// where ToString(c.IndependenceDay) ==' '
// select c.Name;
// List of all eurapion country in ascending order that has poulation less than 500k
var result2 = from c in countries
orderby c.Name
where c.Population < 500000
select c.Name;
}
}
public void LearnRestrictions()
{
List <Country> countries = Country.GetCountries();
var asianCountries = from member in countries
where member.Continents == Continents.Asia
select member;
foreach (var member in asianCountries)
{
Console.WriteLine(member.Name);
}
//HW1: List of countries in Europe Which Have population less <10k
var europeanCountries = from member in countries
where (member.Continents == Continents.Europe) && (member.Population < 10000)
select member;
Console.WriteLine("List of Europen countries which has population less than 10K are:");
foreach (var member in europeanCountries)
{
Console.WriteLine(member.Name);
}
//HW2: List of asian countries which are not ever invaded.
var nonColonizedAsian = from member in countries
where (member.Continents == Continents.Asia) && (member.IndependenceDay == default)
select member;
Console.WriteLine("List asian countries which are not ever invaded:");
foreach (var member in nonColonizedAsian)
{
Console.WriteLine(member.Name);
//HW - Isthere any african county in yr collection.
//HW - Print first two largest asian countryies names.
// HW 1 - Is there any African country in your country collection
var africanMember = countries.Any(x => x.Continents == Continents.Africa);
if (africanMember)
{
Console.WriteLine("List contains african member");
}
else
{
Console.WriteLine("List doesn't contain african member");
}
//Hw 2- Print First 2 largest asian country names.
var areaOrderedList = countries.OrderByDescending(x => x.Area);
var firstTwoLargestCountry = areaOrderedList.Take(2);
Console.WriteLine("Two largest members are:");
foreach (var item in firstTwoLargestCountry)
{
Console.WriteLine(item.Name);
}
}
}