using System; using System.Collections.Generic; using System.Linq; using System.Text; public class CaseInsensitiveComparer : IComparer<string> { public int Compare(string x, string y) { return string.Compare(x, y, true); } } public class MainClass { public static void Main() { string[] words = { "a", "A", "b", "B", "C", "c" }; var sortedWords = words.OrderBy(a => a.Length) .ThenByDescending(a => a, new CaseInsensitiveComparer()); foreach (var s in sortedWords) { Console.WriteLine(s); } } }
LINQ
TakeWhile with two parameters
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
public static void Main() {
string[] presidents = {“ant”, “Hard”, “Harrison”, “Hayes”, “Hoover”, “Jack”};
IEnumerable
.TakeWhile((s, i) => s.Length < 10 && i < 5);
foreach (string item in items)
Console.WriteLine(item);
}
}
[/csharp]
TakeWhile with expresion
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
public static void Main() {
string[] presidents = {“1234567890123”, “Art”, “Buch”, “Bush”, “Car”, “land”};
IEnumerable
TakeWhile with condition
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass{
public static void Main() {
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var firstNumbersLessThan6 = numbers.TakeWhile(n => n < 6); Console.WriteLine("First numbers less than 6:"); foreach (var n in firstNumbersLessThan6) { Console.WriteLine(n); } } } [/csharp]
Use TakeWhile with index
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, 3, 5, 4}; var query = numbers.TakeWhile(( n, index) => n >= index); var query2 = numbers.SkipWhile(( n, index) => n >= index); } }
Nested Take
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
public static void Main() {
List
var first3WAOrders = (
from c in customers
from o in c.Orders
where c.Region == “R1”
select new { c.CustomerId, o.Id, o.OrderDate })
.Take(3);
Console.WriteLine(“First 3 orders in WA:”);
foreach (var order in first3WAOrders) {
Console.WriteLine(order);
}
}
static List
List
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
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
public string CompanyName { get; set; }
public string Region { get; set; }
public List
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.CompanyName, this.Region);
}
int IComparable
if (other == null)
return 1;
if (this.CustomerId > other.CustomerId)
return 1;
if (this.CustomerId < other.CustomerId)
return -1;
return 0;
}
}
class Product : IComparable
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
if (other == null)
return 1;
if (this.Id > other.Id)
return 1;
if (this.Id < other.Id) return -1; return 0; } } [/csharp]
Partitioning Operators: uses Take to generate a sequence of the first three elements of an integer array.
using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass { public static void Main() { int[] numbers = { 5, 4, 1, 3, 9}; var first3Numbers = numbers.Take(3); Console.WriteLine("First 3 numbers:"); foreach (var n in first3Numbers) { Console.WriteLine(n); } } }