C# Linq操作List或數組

Linq對數組操作分爲合併、交集、差集等。

List<int> numbers1 = new List<int>() { 1, 3, 5 };
List<int> numbers2 = new List<int>() { 3,5,11, 13, 15 };

//合併排序
var newList = numbers1.Concat(numbers2).OrderBy(n => n);
foreach (var item in newList)
{
    Console.WriteLine(item);
}

//合併數組，並去除重複，排序
var newList = numbers1.Concat(from n in numbers2 where !numbers1.Contains(n) select n).OrderBy(n => n);
foreach (var item in newList)
{
    Console.WriteLine(item);
}

//合併，去重，排序
var newList = numbers1.Union(numbers2).OrderBy(n => n);
foreach (var item in newList)
{
    Console.WriteLine(item);
}

//取兩個數組交集，排序
var newList = numbers1.Intersect(numbers2).OrderBy(n => n);
foreach (var item in newList)
{
    Console.WriteLine(item);
}

//取出數組1與數組2的差集，排序
var newList = numbers1.Except(numbers2).OrderBy(n => n);
foreach (var item in newList)
{
    Console.WriteLine(item);
}

//判斷兩個數組是否有交集
var exists = numbers1.Exists(delegate(int n)
{
    return numbers2.Exists(delegate(int i)
    {
        if (n == i)
            return true;
        else return false;
    });
});
Console.WriteLine(exists);