Csharp/C Sharp/LINQ/Union
Содержание
prints the unique elements of two integer arrays
<source lang="csharp"> using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 }; int[] numbersB = { 1, 3, 5, 7, 8 }; var uniqueNumbers = numbersA.Union(numbersB); Console.WriteLine("Unique numbers from both arrays:"); foreach (var n in uniqueNumbers) { Console.WriteLine(n); } }
}
</source>
prints unique letters from Product and Customer names
<source lang="csharp"> using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { List<Product> products = GetProductList(); List<Customer> customers = GetCustomerList(); var productFirstChars = from p in products select p.ProductName[0]; var customerFirstChars = from c in customers select c.rupanyName[0]; var uniqueFirstChars = productFirstChars.Union(customerFirstChars); Console.WriteLine("Unique first letters from Product names and Customer names:"); foreach (var ch in uniqueFirstChars) { Console.WriteLine(ch); } } static List<Product> GetProductList() { List<Product> empTree = new List<Product>(); empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); return empTree; } static List<Customer> GetCustomerList() { List<Product> empTree = new List<Product>(); empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); List<Customer> l = new List<Customer>(); l.Add(new Customer { CompanyName = "A", Region = "R1", UnitsInStock = 1, Orders = empTree, CustomerId = 0 }); l.Add(new Customer { CompanyName = "B", Region = "R2", UnitsInStock = 2, Orders = empTree, CustomerId = 1 }); l.Add(new Customer { CompanyName = "C", Region = "R3", UnitsInStock = 3, Orders = empTree, CustomerId = 2 }); l.Add(new Customer { CompanyName = "D", Region = "R4", UnitsInStock = 4, Orders = empTree, CustomerId = 3 }); l.Add(new Customer { CompanyName = "E", Region = "R5", UnitsInStock = 5, Orders = empTree, CustomerId = 4 }); return l; }
} class Customer : IComparable<Customer> {
public string CompanyName { get; set; } public string Region { get; set; } public List<Product> Orders { get; set; } public int UnitsInStock { get; set; } public int CustomerId { get; set; } public override string ToString() { return String.Format("Id: {0}, Name: {1}, Region: {3}", this.CustomerId, this.rupanyName, this.Region); } int IComparable<Customer>.rupareTo(Customer other) { if (other == null) return 1; if (this.CustomerId > other.CustomerId) return 1; if (this.CustomerId < other.CustomerId) return -1; return 0; }
} class Product : IComparable<Product> {
public string ProductName { get; set; } public string Category { get; set; } public int UnitPrice { get; set; } public int UnitsInStock { get; set; } public int Total { get; set; } public DateTime OrderDate { get; set; } public int Id { get; set; } public override string ToString() { return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category); } int IComparable<Product>.rupareTo(Product other) { if (other == null) return 1; if (this.Id > other.Id) return 1; if (this.Id < other.Id) return -1; return 0; }
}
</source>
Union does appends one sequence to another with duplicates removed:
<source lang="csharp"> using System; using System.Collections.Generic; using System.Linq; public class MainClass {
public static void Main() { int[] seq1 = { 1, 2, 3 }; int[] seq2 = { 3, 4, 5 }; IEnumerable<int> concat = seq1.Concat(seq2); // { 1, 2, 3, 3, 4, 5 } IEnumerable<int> union = seq1.Union(seq2); // { 1, 2, 3, 4, 5 } }
}
</source>
Union Operator
<source lang="csharp"> using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MainClass {
public static void Main() { string[] presidents = {"ant", "arding", "arrison", "eyes", "over", "ackson"}; IEnumerable<string> first = presidents.Take(5); IEnumerable<string> second = presidents.Skip(4); IEnumerable<string> concat = first.Concat<string>(second); IEnumerable<string> union = first.Union<string>(second); Console.WriteLine("The count of the array is: " + presidents.Count()); Console.WriteLine("The count of the first sequence is: " + first.Count()); Console.WriteLine("The count of the second sequence is: " + second.Count()); Console.WriteLine("The count of the concat sequence is: " + concat.Count()); Console.WriteLine("The count of the union sequence is: " + union.Count()); }
}
</source>
Use Linq to union two arrays
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Text; using System.Linq; public class MainClass{
public static void Main(){ int[] numbers = {1, 1, 3, 3}; int[] numbers2 = {1, 2, 3, 4}; Console.Write(numbers.Union(numbers2)); }
}
</source>