static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//LINQ Extensions Methods
var cheapBooks = books
.Where(b => b.Price < 10);
var cheapBooksOrderedByTitle = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title);
var stringListOfcheapBooksOrderedByTitle = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
//Fin LINQ Extensions Methods
//LINQ Query Operators, this always start with "from" and always finish with the "select"
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
//Fin LINQ Query Operators
//LINQ Extensions Methods, this method goes to an error if there is not any book with that title
//to avoid it we can use "SingleOrDefault" line 40
var book = books.Single(b => b.Title == "ASP.NET MVC");
//If there is not object matching this condition the Default value will be return which in this case would be null
var book1 = books.SingleOrDefault(b => b.Title == "ASP.NET MVC++");
//These are used for paging data, this means skip to record/object and takes three
var bookList = books.Skip(2).Take(3);
foreach (var pagedBook in bookList)
{
Console.WriteLine(pagedBook.Title);
}
var priceOfMoreExpensiveBook = books.Max(b => b.Price);
var priceOfCheapestBook = books.Min(b => b.Price);
var totalPrices = books.Sum(b => b.Price);
var averages = books.Average(b => b.Price);
}
static void Main(string[] args)
{
var books = new BookRepository().Getbooks();
foreach (var book in books)
{
Console.WriteLine("Book Title :" + book.Title);
Console.WriteLine("Price :" + book.Price + "$");
}
//Display books less than 10$ without LINQ
var cheapBooks = new List <Book>();
foreach (var book in books)
{
if (book.Price < 10)
{
cheapBooks.Add(book);
}
}
Console.WriteLine();
Console.WriteLine("***BOOKS UNDER 10$***");
foreach (var cheapBook in cheapBooks)
{
Console.WriteLine("Book Title :" + cheapBook.Title);
Console.WriteLine("Price :" + cheapBook.Price + "$");
}
//With LINQ Extension Methods
//Books under 10,Order By Price and show only Title
var cheapBooksLINQ = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Price)
.Select(b => b.Title);
Console.WriteLine();
Console.WriteLine("***BOOKS UNDER 10$ with LINQ***");
foreach (var cheapBook in cheapBooksLINQ)
{
Console.WriteLine("Book Title :" + cheapBook);
}
//With LINQ Query Operators
var cheaperBooksLINQ = from b in books
where b.Price < 10
orderby b.Price
select b;
Console.WriteLine();
Console.WriteLine("***BOOKS UNDER 10$ with LINQ***");
foreach (var cheaperBook in cheaperBooksLINQ)
{
Console.WriteLine("Book Title :" + cheaperBook.Title);
Console.WriteLine("Price :" + cheaperBook.Price);
}
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//LINQ Query Operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
//LINQ extension methods
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
//var book = books.Single(b => b.Title == "ASP.NET MVC++");//Burada patlayacaktır. Single tek bir sonuç arar. Birden çok sonuç dönerse de patlar.
//var book = books.SingleOrDefault(b => b.Title == "ASP.NET MVC++");//returns null
//var book = books.First(b => b.Title == "C# Advanced Topics");
//var bookLast = books.Last(b => b.Title == "C# Advanced Topics");
//Console.WriteLine(book.Title+" "+book.Price+"\n"+ bookLast.Title + " " + bookLast.Price);
var pagedBooks = books.Skip(2).Take(3);
foreach (var b in pagedBooks)
{
Console.WriteLine(b.Title);
}
var count = books.Count();
var maxBook = books.Max(b => b.Price);
var minBook = books.Min(b => b.Price);
var total = books.Sum(b => b.Price);
//Console.WriteLine(maxBook);
//Console.WriteLine(minBook);
//Console.WriteLine(total);
}
static void Main(string[] args)
{
var library = new BookRepository().GetBooks();
// With LINQ Query Operators
var cheaperBooks =
from book in library
where book.Price < 10
orderby book.Title
select book.Title;
// With LINQ extension methods
var cheapBooks = library
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
Nullable <DateTime> date = null;
DateTime? dateAgain = null;
foreach (var title in cheapBooks)
{
Console.WriteLine(title);
}
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
// LINQ Query Operators [always start with the from and end with select]
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// With LINQ Extension Methods
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
foreach (var book in cheapBooks)
{
//Console.WriteLine(book.Title + " " + book.Price);
Console.WriteLine(book);
}
// SINGLE OBJECT
var book1 = books.SingleOrDefault(books => books.Title == "ASP.NET MVC");
Console.WriteLine(book1.Title);
// first object
var book2 = books.First(b => b.Title == "How to code");
Console.WriteLine(book2.Title + " " + book2.Price);
// last
var book3 = books.LastOrDefault(books => books.Title == "ASP.NET MVC");
Console.WriteLine(book3.Title + " " + book3.Price);
// skip
var pagedBooks = books.Skip(2).Take(3);
Console.WriteLine("\nLast 3 books: ");
foreach (var pageBook in pagedBooks)
{
Console.WriteLine(pageBook.Title);
}
// count
Console.WriteLine($"There are {books.Count()} books. ");
Console.WriteLine($"The highest priced book is P{books.Max(b => b.Price)}");
}
//Definition of LINQ
//Stands for Language Integrated Query
//Capability to query objects
//Usage
//You can query objects in memory (LINQ to objects), Databases (LINQ to Entities), XML (LINQ to XML), ADO.NET Data Sets (LINQ to Data Sets)
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//LINQ Query Operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
//LINQ Extension Methods
books.Where(x => x.Price < 10).ToList().ForEach(y => Console.WriteLine(y.Title));
}
static void Main(string[] args)
{
//Another example
//Worker work = new Worker();
#region LINQExample1
var books = new BookRepository().GetBooks();
//LINQ Query Operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
//Use link instead of the below code
/*var cheapBooks = new List<Book>();
* //foreach(var book in books)
* //{
* // if (book.Price < 10)
* // cheapBooks.Add(book);
* }*/
//LINQ Extension Methods
var cheapBooks = books.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
//foreach (var book in cheapBooks)
// Console.WriteLine(book);
// Console.WriteLine(book.Title + " " + book.Price);
#endregion
//will generate an error if item not found
var book = books.Single(b => b.Title == "ASP.NET MVC");
//Will return Null
var bookz = books.SingleOrDefault(b => b.Title == "ASP.NET MVC");
//Gets the first item with the indicated value
//var bookzz = books.First(b => b.Title == "C# Advanced Topics");
var bookzz = books.FirstOrDefault(b => b.Title == "C# Advanced Topics");
var bookzzz = books.Skip(2).Take(3);
Console.WriteLine(book.Title);
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//Linq query operators
var cheaperBooks =
from b in books
where b.Price < 10
orderby b.Title
select b;
//Linq extension methods
var cheapestBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
var single = books.First(b => b.Title == "C# Advanced topics");
Console.WriteLine(single.Title + " " + single.Price + "\n");
var count = books.Count();
Console.WriteLine(count);
var max = books.Max(b => b.Price);
Console.WriteLine(max);
var min = books.Max(books => books.Price);
Console.WriteLine(min);
var totalPrices = books.Sum(b => b.Price);
Console.WriteLine(totalPrices);
foreach (var book in cheapestBooks)
{
// Console.WriteLine(book.Title + " " + book.Price);
Console.WriteLine(book);
}
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
var cheapBooks = books.Where(b => b.Price > 10).OrderBy(b => b.Title).Select(b => b.Title);
foreach (var book in cheapBooks)
{
Console.WriteLine(book.Title + " " + book.Price);
}
/*var book = books.Single(b.Title == "ASP.NET MVC");
* Console.WriteLine(book.Title);
*
* var book = books.SingleOrDefault(b.Title == "ASP.NET MVC");
* Console.WriteLine(book.Title);
*
* var book = books.First(b.Title == "ASP.NET MVC");
* Console.WriteLine(book.Title + " " + book.Price);
*
* var pagedBooks = books.Skip(2).Take(3);
* foreach (var pagedBook in pagedBooks)
* Console.WriteLine(pagedBook.Title);
*
* var maxPrice = books.Max(b => b.Price);
* var minPrice = books.Min(b => b.Price);
* var count = books.Count();
* Console.WriteLine(maxPrice);
* Console.WriteLine(minPrice);
* Console.WriteLine(count); */
/* LINQ extension methods
* var cheapBooks = books
* .Where(b => b.price > 10)
* .OrderBy(b => b.Title)
* .Select(b => b.Title); */
/* LINQ query operators
* var cheapBooks =
* from b in books
* where b.Price < 10
* orderby b.Title
* select b.title; */
}
//Lesson 6 : LINQ
static void Main(string[] args)
{
//LINQ Extension Methods
var books = new BookRepository().GetBooks();
var cheapBooks = books.Where(x => x.Price < 10).Select(x => x.Title);
foreach (var book in cheapBooks)
{
//Console.WriteLine(book.Title);
Console.WriteLine(book);
}
//LINQ Queries
var cheapBooks2 = from b in books
where b.Price < 10
select b.Title;
foreach (var book in cheapBooks2)
{
//Console.WriteLine(book.Title);
Console.WriteLine(book);
}
Console.WriteLine("-----------");
//Return a single book
//var singleBook = books.Single(b => b.Title == "Title 3");
var singleBook = books.SingleOrDefault(b => b.Title == "Title 3");
Console.WriteLine(singleBook.Title);
//Skip data
Console.WriteLine("-----------");
var chosenBooks = books.Skip(2);
foreach (var book in chosenBooks)
{
Console.WriteLine(book.Title);
}
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
var cheapBooks = books.Where(b => b.Price < 10);
// LINQ Query Operator
var cheaperBooks =
from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// LINQ Methods can be chained
var orderedByTitle = books
.OrderBy(b => b.Title)
.Select(b => b.Title);
foreach (var b in orderedByTitle)
{
Console.WriteLine(b);
}
// Other Examples
var result1 = books.Single(book => book.Title == "A");
var result2 = books.SingleOrDefault(b => b.Title == "A");
var result3 = books.FirstOrDefault(b => b.Title == "A");
var result4 = books.LastOrDefault(b => b.Title == "A");
var result5 = books.Skip(2).Take(3);
var result6 = books.Count();
var result7 = books.Max(b => b.Price);
var result8 = books.Sum(b => b.Price);
var result9 = books.Average(b => b.Price);
Console.ReadLine();
}
public void Exercise1()
{
var books = new BookRepository().GetBooks();
//LINQ Query operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// LINQ extension methods
var cheapBooks = books.Where(x => x.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
foreach (var book in cheapBooks)
{
Console.WriteLine(book);
}
Console.ReadLine();
}
static void Main(string[] args)
{
var people = new List <Person>()
{
new Person()
{
Name = "Anastasia", Job = "Developer"
},
new Person()
{
Name = "Dzmitry", Job = "Developer"
},
new Person()
{
Name = "Peter", Job = "Bookeeper"
},
new Person()
{
Name = "Josh", Job = "Cook"
},
new Person()
{
Name = "Aaron", Job = "Cook"
},
new Person()
{
Name = "Anastasia", Job = "Server"
},
};
var anastasias = from p in people
where p.Job == "Developer"
select p;
foreach (var anastasia in anastasias)
{
Console.WriteLine(anastasia.Job);
Console.WriteLine(anastasia.Name);
}
var books = new BookRepository().GetBooks();
//With select you can select by property
var cheapBooksTitles = books
.Where(b => b.Price < 10)
.Where(b => b.Price < 10)
.Select(b => b.Title);
// Linq query Operator like a SQL
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// Returning Single Book or Operator || SingleOrDefault will return null as a value
var singleBook = books.SingleOrDefault(b => b.Title == "ASP.NET MVC");
Console.WriteLine(singleBook.Price);
// can find the first value that matche the query || FirstOrDefalult
Console.WriteLine(books.First(b => b.Title == "C# Advanced Topics").Title);
// Last || LastOrDefault
Console.WriteLine(books.Last(b => b.Title == "C# Advanced Topics").Title);
// Skiping the data
Console.WriteLine(books.Skip(2).Take(3).Select(b => b.Title));
// Aggregators
Console.WriteLine("Aggregators");
Console.WriteLine(books.Count());
//Max Price
Console.WriteLine(books.Max(x => x.Price));
// Cheppest Price
Console.WriteLine(books.Min(x => x.Price));
// Sum
Console.WriteLine(books.Sum(b => b.Price));
// Aggregate fuinctions
var list = new List <int>()
{
13, 18, 25, 12, 16
};
list.Aggregate((a, b) => a + b);
// Get Avarage
var avgPrice = books.Average(b => b.Price);
Console.WriteLine("The avarage book price is {0} ", avgPrice);
foreach (var s in books.Skip(2).Take(3).Select(b => b.Title))
{
Console.WriteLine("Skipped Book {0} ", s);
}
foreach (var cheapBooksTitle in cheapBooksTitles)
{
Console.WriteLine(cheapBooksTitle);
}
foreach (var book in books.OrderBy(b => b.Title).Where(b => b.Price < 10))
{
Console.WriteLine(book.Title);
Console.WriteLine(book.Price);
}
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//LINQ Query Operators
//slightly worse, keywords translate to extension methods
//anyway, and there isnt a keyword for everything. although it is
//friendlier and cleaner.
var cheaperBooks =
from b in books
where b.Price < 10
orderby b.Title
select b;
//LINQ Extension Methods
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
var bookMVC = books.FirstOrDefault(b => b.Title == "C# Advanced Topics");
//var bookMVC = books.LastOrDefault(b => b.Title == "C# Advanced Topics");
//var bookMVC = books.SingleOrDefault(b => b.Title == "ASP.NET MVC+");
if (bookMVC != null)
{
Console.WriteLine(bookMVC.Title + " " + bookMVC.Price);
}
Console.WriteLine("---------------------");
Console.WriteLine("Now trying skip and take");
Console.WriteLine("---------------------");
var pagedBooks = books.Skip(2).Take(3);
foreach (var pagedBook in pagedBooks)
{
Console.WriteLine(pagedBook.Title);
}
var count = books.Count();
Console.WriteLine("---------------------");
Console.WriteLine(count);
var max = books.Max(b => b.Price);
Console.WriteLine("---------------------");
Console.WriteLine(max);
var min = books.Min(b => b.Price);
Console.WriteLine("---------------------");
Console.WriteLine(min);
var totalCost = books.Sum(b => b.Price);
Console.WriteLine("---------------------");
Console.WriteLine(totalCost);
var average = books.Average(b => b.Price);
Console.WriteLine("---------------------");
Console.WriteLine(average);
//Workaround, non-LINQ version
//
//var cheapBooks = new List<Book>();
//foreach (var book in books)
//{
// if (book.Price < 10)
// cheapBooks.Add(book);
//}
//foreach (var book in cheapBooks)
//{
// Console.WriteLine("---------------------");
// Console.WriteLine(book.Title + " " + book.Price);
// Console.WriteLine(book);
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
//LINQ Query Operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
/*---the same -----*/
//LINQ Extension Methods
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
foreach (var bk in cheapBooks)
{
// Console.WriteLine(book.Title);
Console.WriteLine(bk);
}
/*------------------------------------------------------------------*/
var book = books.Single(b => b.Title == "ASP.NET MVC"); //throw an exception if nothing found
var book2 = books.SingleOrDefault(b => b.Title == "ASP.NET MVC++"); //return null if nothing found
Console.WriteLine(book.Title);
Console.WriteLine(book2 == null ? "null" : book2.Title);
/*-------------------------------------------------------------------*/
var book3 = books.First(); //first element of the collection
var book4 = books.First(b => b.Title == "C# Advanced Topics"); //first element of the collection
var book5 = books.FirstOrDefault(); //return null if nothing found
Console.WriteLine(book3.Title);
Console.WriteLine(book4.Price);
Console.WriteLine(book5 == null ? "null" : book5.Title);
var book6 = books.Last(); //first element of the collection
var book7 = books.Last(b => b.Title == "C# Advanced Topics"); //first element of the collection
var book8 = books.LastOrDefault(); //return null if nothing found
Console.WriteLine(book6.Title);
Console.WriteLine(book7.Price);
Console.WriteLine(book8 == null ? "null" : book8.Title);
/*-------------------------------------------------------------------*/
var books9 = books.Skip(2).Take(3); //used for paging data
//skip 2 records or two objects and take 3
foreach (var bb in books9)
{
Console.WriteLine(bb.Title);
}
/* --------------------------------------------------------------------*/
var count = books.Count();
Console.WriteLine(count);
var maxPrice = books.Max(b => b.Price);
var minPrice = books.Min(b => b.Price);
var sumPriceofAllBook = books.Sum(b => b.Price);
var average = books.Average(b => b.Price);
Console.WriteLine("maxPrice : {0} and min price : {1} and sum of all books : {2}, and finally average = {3}", maxPrice, minPrice, sumPriceofAllBook, average);
Console.ReadLine();
}
static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
/*
* This can be done in one line using LINQ:
* var cheapBooks = new List<Book>();
*
* foreach(var book in books)
* {
* if(book.Price < 10)
* {
* cheapBooks.Add(book);
* }
* }
*/
// LINQ Extension methods
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Price)
.Select(b => b.Title);
// LINQ Query operators
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
foreach (var book in cheapBooks)
{
//Console.WriteLine(book.Title + " " + book.Price);
Console.WriteLine(book);
}
Console.WriteLine();
foreach (var book in cheaperBooks)
{
//Console.WriteLine(book.Title + " " + book.Price);
Console.WriteLine(book);
}
Console.WriteLine();
var book1 = books.SingleOrDefault(b => b.Title == "ASP.NET MVC+");
Console.WriteLine(book1);
var book2 = books.FirstOrDefault(b => b.Title == "C# Advanced Topics");
Console.WriteLine(book2.Title + " " + book2.Price);
var book3 = books.LastOrDefault(b => b.Title == "C# Advanced Topics");
Console.WriteLine(book3.Title + " " + book3.Price);
Console.WriteLine();
var books4 = books.Skip(2).Take(3);
foreach (var book in books4)
{
Console.WriteLine(book.Title);
}
Console.WriteLine();
var count = books.Count();
Console.WriteLine(count);
Console.WriteLine();
var maxPrice = books.Max(b => b.Price);
Console.WriteLine(maxPrice);
Console.WriteLine();
var minPrice = books.Min(b => b.Price);
Console.WriteLine(minPrice);
Console.WriteLine();
var totalPrice = books.Sum(b => b.Price);
Console.WriteLine(totalPrice);
}