List<int> list1 = new List<int>(); list1.Add(1); list1.Add(2); list1.Add(3); List<int> list2 = new List<int>(); list2.Add(3); list2.Add(4); list2.Add(5); //得到的结果是4,5 即减去了相同的元素。 List<int> list3 = list2.Except(list1).ToList(); foreach (int i in list3) { MessageBox.Show(i.ToString()); }
合并两个数组,并去掉重复元素,然后排序
List<int> numbers1 = new List<int>() { 5, 4, 1, 3, 9, 8, 6, 7, 12, 10 }; List<int> numbers2 = new List<int>() { 15, 14, 11, 13, 19, 18, 16, 17, 12, 10 }; var newQuerty = numbers1.Concat( from n in numbers2 where !numbers1.Contains(n) select n ).OrderBy(n=>n);
合并两个数组，并去除合并后的重复数据， 并排序
int[] A={1,2,2,3,4,5,6,6,6}; int[] B={2,2,2,3,7,8,9,5}; List<int> list = new List<int>(A); list.AddRange(B); list.Sort(); //去除重复项 foreach (int i in list.Distinct<int>()) { Console.WriteLine(i); }
取两个数组的相同元素
string[] names = {"Adams","Arthur","Buchanan","Tsbuchis","ShCian","FuchsiaLinda","DecheChen","Lotheer","FindLanciCade","SorchLand","JiangZheng","MisiiLoda","Gtod","Dfac","Lama","BakCades","Losangle","ZheWQ","GehengDahaLothi","ToryLandey","DakaLothy","BthLanda","MenNorth","Fith","FoxMain","DontM","Saobba","Del","Sala","Ghero","BhthLaPhda"}; IEnumerable<string> skip = names.Skip(10); IEnumerable<string> take = names.Take(11); //取出两个序列中交集部分，按理论应该输出JiangZheng IEnumerable<string> intersect = skip.Intersect(take);//取出交集 foreach(varsinintersect) { Console.WriteLine(s); }
///Take(); int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var first3Numbers = numbers.Take(3); //从第一个元素开始,获取三个 return的是前面的数 Console.WriteLine("First 3 numbers:"); foreach (var n in first3Numbers) { Console.WriteLine(n);//结果 5 4 1 } ///TakeWhile() int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; //在这里需要注意.使用TakeWhile获取小于6的元素,是从第一个元素开始, //一直到不满足其小于6这个条件为止.也就是执行到和9这个元素比较后,就结束比较了 //可以想象一下执行过程. //5<6=true;4<6=true;1<6=true;3<6=true //9<6=false; 这里就停止继续比较了 var firstNumbersLessThan6 = numbers.TakeWhile(n => n < 6); Console.WriteLine("First numbers less than 6:"); foreach (var n in firstNumbersLessThan6) { Console.WriteLine(n);//结果为 5 4 1 3 } ///Skip() /// /// int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var allButFirst4Numbers = numbers.Skip(4); //跳过前四个元素,获取后面所有的元素 Console.WriteLine("All but first 4 numbers:"); foreach (var n in allButFirst4Numbers) { Console.WriteLine(n);//结果9 8 6 7 2 0 } //SkipWhile() int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; //跳过不能被3整除的所有元素 //这里和TakeWhiel又有些不一样。 //TakeWhile遇到条件不满足的时候,就会return, //但是SkipWhile如果执行到能被三整除的数,那么其后面的元素就不会继续比较了 //同样,想象一下执行过程 //5%3!=0==true; 4%3!=0==true; 1%3!=0==true; //3%3!=0==false; 运行到这里的时候,后面的就不再比较. //所以输出结果中会有8、7、2、0这几个不满足条件的元素 var allButFirst3Numbers = numbers.SkipWhile(n => n % 3 != 0); foreach (var n in allButFirst3Numbers) { Console.WriteLine(n);//结果3 9 8 6 7 2 0 } Console.ReadKey();
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; namespace test { class Program { static void Main(string[] args) { IList<Student> oneStudents = new List<Student>(); oneStudents.Add(new Student(1,false,"小新1","徐汇")); oneStudents.Add(new Student(2,false,"小新2","闵行")); oneStudents.Add(new Student(3, false, "小新3", "嘉定")); oneStudents.Add(new Student(4, false, "小新4", "闸北")); IList<Student> twoStudents = new List<Student>(); twoStudents.Add(new Student(5, false, "小新5", "贵州")); twoStudents.Add(new Student(6, false, "小新6", "湖北")); twoStudents.Add(new Student(7, false, "小新7", "山东")); twoStudents.Add(new Student(8, false, "小新8", "西藏")); IList<Student> threeStudents = new List<Student>(); threeStudents.Add(new Student(1, false, "小新1", "徐汇")); threeStudents.Add(new Student(2, false, "小新2", "闵行")); var bingji = oneStudents.Union(twoStudents, new StudentListEquality()).ToList();//并（全）集 var jiaoji = oneStudents.Intersect(threeStudents, new StudentListEquality()).ToList();//交集 var chaji = oneStudents.Except(threeStudents, new StudentListEquality()).ToList();//差集 Console.WriteLine(); Console.WriteLine("以下是并集的结果"); bingji.ForEach(x => { Console.WriteLine(x.StudentId.ToString() + " " + x.Sex.ToString() + " " + x.Name.ToString()+" "+x.Address.ToString()); }); Console.WriteLine(); Console.WriteLine("以下是交集的结果"); jiaoji.ForEach(x => { Console.WriteLine(x.StudentId.ToString() + " " + x.Sex.ToString() + " " + x.Name.ToString() + " " + x.Address.ToString()); }); Console.WriteLine(); Console.WriteLine("以下是差集的结果"); chaji.ForEach(x => { Console.WriteLine(x.StudentId.ToString() + " " + x.Sex.ToString() + " " + x.Name.ToString() + " " + x.Address.ToString()); }); } } public class Student { public Student(int studentId, bool sex, String name, String address) { this.StudentId = studentId; this.Sex = sex; this.Name = name; this.Address = address; } public int StudentId { get; set; } public bool Sex { get; set; } public String Name { get; set; } public String Address { get; set; } } public class StudentListEquality : IEqualityComparer<Student> { public bool Equals(Student x, Student y) { return x.StudentId == y.StudentId; } public int GetHashCode(Student obj) { if (obj == null) { return 0; } else { return obj.ToString().GetHashCode(); } } } }
以上运行的结果是：
以上的结果是重载了含有参数的IEqualityComparer<TSource> 方法，实现IEqualityComparer接口 对数据进行了重复过滤，如果不实现这个方法结果是
var bingji = oneStudents.Union(twoStudents).ToList();//并（全）集 var jiaoji = oneStudents.Intersect(threeStudents).ToList();//交集 var chaji = oneStudents.Except(threeStudents).ToList();//差集
但是对于List<T>的T是简单类型，如int string long 。。。。。是怎么样的呢？代码如下所示
IList<int> firstNumbers = new List<int>() { 1,2,3,4,5,6,7 }; IList<int> secondNumbers = new List<int>() { 8,9,10 }; IList<int> thressNumbers = new List<int>() { 1,2,3 }; var result1 = firstNumbers.Union(secondNumbers).ToList(); var result2 = firstNumbers.Intersect(thressNumbers).ToList(); var result3 = firstNumbers.Except(thressNumbers).ToList(); Console.WriteLine("以下是并集的结果"); result1.ForEach(x => Console.WriteLine(x)); Console.WriteLine(); Console.WriteLine("以下是交集的结果"); result2.ForEach(x => Console.WriteLine(x)); Console.WriteLine(); Console.WriteLine("以下是差集的结果"); result3.ForEach(x => Console.WriteLine(x)); Console.WriteLine("以上是简单类型如：int string long。。。。。没有实现IEqualityComparer<T>接口");
