通过查看字符串列表来获取与字符串中的字符串匹配的字符串列表的最佳方法是什么？

Question

Basically I have a string array that I am using to match inside a single string:

string[] matches = { "{A}", "{B}", "{CC}" };

Then I from these I look if I find any of these inside my string:

string text = "Lorem Ipsum is {CC} simply dummy text {A} of the {CC} printing and typesetting industry {B}."

In which case, the resulting array I want to gather should be:

string[] allmatches = { "{CC}", "{A}", "{CC}", "{B}" };

Is there an easy way to do this using LINQ or maybe Regex?

Answer 1

Assuming, that {A}..{Z} are the only matches required, we can try combining Regex and Linq, eg

  string text = 
    @"Lorem Ipsum is {C} simply dummy text {A} of the {C} printing and typesetting industry {B}.";

  string[] allmatches = Regex
    .Matches(text, @"\{[A-Z]\}")
    .Cast<Match>()
    .Select(m => m.Value)
    //.Where(item => matches.Contains(item)) // uncomment to validate matches
    .ToArray();

Let's have a look:

  Console.Write(string.Join(", ", allmatches));

Outcome:

  {C}, {A}, {C}, {B}

Edit: uncomment .Where(...) if you want matches which are in matches[] only

Edit 2: If match doesn't necessary contain one letter only, change pattern:

  .Matches(text, @"\{[A-Z]+\}")    // one or more capital letters
  .Matches(text, @"\{[a-zA-Z]+\}") // one or more English letters
  .Matches(text, @"\{\p{L}+\}")    // one or more Unicode letters
  .Matches(text, @"\{[^}{]+\}")    // one or more characters except "{" and "}" 

Answer 2

Construct the regex by first Escape ing each element in matches using Select , then Join ing with | . After that, get the Matches of the regex against text and Select the Value s:

var regex = string.Join("|", matches.Select(Regex.Escape));
var result = Regex.Matches(text, regex)
            .Cast<Match>()
            .Select(x => x.Value).ToArray();