Linq101-Set

using System;
using System.Collections.Generic;
using System.Linq;

namespace Linq101
{
    class Set
    {
        /// <summary>
        /// This sample uses Distinct to remove duplicate elements in a sequence of factors of 300.
        /// </summary>
        public void Linq46()
        {
            int[] factorsOf300 = { 2, 2, 3, 5, 5 };

            var uniqueFactors = factorsOf300.Distinct();

            Console.WriteLine("300的因数：");
            foreach (var factor in uniqueFactors)
            {
                Console.WriteLine(factor);
            }
        }

        /// <summary>
        /// This sample uses Distinct to find the unique Category names.
        /// </summary>
        public void Linq47()
        {
            List<Data.Product> products = Data.GetProductList();

            var categoryNames = (from p in products
                                 select p.Category).Distinct();

            Console.WriteLine("种类名称：");
            ObjectDumper.Write(categoryNames);
        }

        /// <summary>
        /// This sample uses Union to create one sequence that contains the unique values from both arrays.
        /// </summary>
        public void Linq48()
        {
            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:");
            ObjectDumper.Write(uniqueNumbers);
        }

        /// <summary>
        /// This sample uses Union to create one sequence that contains the unique first letter from both product and customer names.
        /// </summary>
        public void Linq49()
        {
            List<Data.Product> products = Data.GetProductList();
            List<Data.Customer> customers = Data.GetCustomerList();

            var productFirstChar = from p in products select p.ProductName[0];
            var customerFirstChar = from c in customers select c.CompanyName[0];

            var uniqueFirstChar = productFirstChar.Union(customerFirstChar);

            Console.WriteLine("Unique First Char:");
            ObjectDumper.Write(uniqueFirstChar);
        }

        /// <summary>
        /// This sample uses Intersect to create one sequence that contains the common values shared by both arrays.
        /// </summary>
        public void Linq50()
        {
            int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
            int[] numbersB = { 1, 3, 5, 7, 8 };

            var commonNumbers = numbersA.Intersect(numbersB);

            Console.WriteLine("共有的数字：");
            ObjectDumper.Write(commonNumbers);
        }

        /// <summary>
        /// This sample uses Intersect to create one sequence that contains the common first letter from both product and customer names.
        /// </summary>
        public void Linq51()
        {
            List<Data.Product> products = Data.GetProductList();
            List<Data.Customer> customers = Data.GetCustomerList();

            var productFirstChar = from p in products select p.ProductName[0];
            var customerFirstChar = from c in customers select c.CompanyName[0];

            var commonFirstChar = productFirstChar.Intersect(customerFirstChar);

            Console.WriteLine("Common First Char");
            ObjectDumper.Write(commonFirstChar);
        }

        /// <summary>
        /// This sample uses Except to create a sequence that contains the values from numbersAthat are not also in numbersB.
        /// </summary>
        public void Linq52()
        {
            int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
            int[] numbersB = { 1, 3, 5, 7, 8 };

            var aOnlyNumbers = numbersA.Except(numbersB);

            Console.WriteLine("Numbers in arrayA but no ArrayB");
            ObjectDumper.Write(aOnlyNumbers);
        }

        /// <summary>
        /// This sample uses Except to create one sequence that contains the first letters of product names that are not also first letters of customer names.
        /// </summary>
        public void Linq53()
        {
            List<Data.Product> products = Data.GetProductList();
            List<Data.Customer> customers = Data.GetCustomerList();

            var productFirstChar = from p in products select p.ProductName[0];
            var customerFirstChar = from c in customers select c.CompanyName[0];

            var productOnlyFirstChar = productFirstChar.Except(customerFirstChar);

            Console.WriteLine("First char only in productFirstChar");
            ObjectDumper.Write(productOnlyFirstChar);
        }
    }
}