20190404-C#學習日誌

// LINQ

//架構
// from
// where
// select
// using System.Linq

int [] numbers = {0, 1, 2, 3, 4, 5, 6};

var evenNumQuery =
     from num in numbers
     where (num % 2 == 0)
     select num;

foreach(int i in evenNumQuery)
{
     Console.WriteLine("{0} is an even number", i);
}

/*--------------------------------------------------------------------------------------------------*/

using System.Linq
using System.Collections.Generic

public static void Main(string [] args)
{
     List<Customer> customers = new List<Customer>();
     customers.Add(new Customer("Alan", 25.60));
     customers.Add(new Customer("Bill", -32.1));
     customers.Add(new Customer("Carl", -12.2));
     customers.Add(new Customer("David", 12.6));

     var overdue =
     from cust in customers
     where cust.Balance < 0

     //排列，並且從小排到大
     orderby cust.Balance ascending

     //排列，並且從大排到小
     //orderby cust.Balance descending
    
     //選擇多個屬性
     select new{cust.Name, cust.Balance};

     foreach(var cust in overdue)
     {
          Console.WriteLine("Name = {0}, Balance = {1}", cust.Name, cust.Balance)
     }
}