c# - 从字符串中删除重复值

Question

我有两个字符串

string s1 = "Apple, Mango, Cherry";
string s2 = "Apple, Mango, Cherry, Pear";

现在我想比较两个字符串并删除重复值和结果应该是

string s3 = "Pear"

怎么做？

我试过:

List<string> list1 = new List<string> {CommonJurisdictions };
List<string> list2 = new List<string> { Jurisdiction };
List<string> ulist = list2.Except(list1).ToList();

但它没有给出预期的结果。

Answer 1

使用 String.Split , Enumerable.Except , Concat和 String.Join

string s1 = "Apple, Mango, Cherry";
string s2 = "Apple, Mango, Cherry, Pear";

var s1Token = s1.Split(',').Select(t => t.Trim()).ToArray();
var s2Token = s2.Split(',').Select(t => t.Trim()).ToArray();
var inSecondNotFirst = s1Token.Except(s2Token);
var inFirstNotSecond = s2Token.Except(s1Token);
string s3 = String.Join(", ", inSecondNotFirst.Concat(inFirstNotSecond));

但更有效的 ( O(n) ) 是使用 HashSet<T>它是 SymmetricExceptWith :

 var s1Token = new HashSet<string>(s1.Split(',').Select(t => t.Trim()));
 var s2Token = new HashSet<string>(s2.Split(',').Select(t => t.Trim()));
 s1Token.SymmetricExceptWith(s2Token);
 string s3 = String.Join(", ", s1Token);