c# - 找出有多少字符串匹配

Question

假设我有两个字符串:

"SomeTextHereThatIsTheSource"
"SomeTextHereThatIsCloseToTheSourceButNotTheSame"

有没有一种巧妙的 .net 方法可以知道文本的哪一部分是相同的(从头开始)。

所以在这个例子中，结果将是:

"SomeTextHereThatIs"

Answer 1

您可以使用 TakeWhile:

string MatchFromStart(string s1, string s2)
{
    if (s1 == null || s2 == null) return "";

    var matchingArray = s1.TakeWhile((c, i) => { return i < s2.Length && c == s2[i]; });
    return String.Join("", matchingArray);
}

然后使用它:

string s1 = "SomeTextHereThatIsTheSource";
string s2 = "SomeTextHereThat";
string s3 = "SomeTextHereThatIsCloseToTheSourceButNotTheSame";
Console.WriteLine(MatchFromStart(s1, s2));   // SomeTextHereThat
Console.WriteLine(MatchFromStart(s2, s1));   // SomeTextHereThat
Console.WriteLine(MatchFromStart(s3, s1));   // SomeTextHereThatIs
Console.WriteLine(MatchFromStart("", s1));   // (blank string)
Console.WriteLine(MatchFromStart(s3, ""));   // (blank string)
Console.WriteLine(MatchFromStart(null, s1)); // (blank string)
Console.WriteLine(MatchFromStart(s2, null)); // (blank string)