如何在 c# 中的两个字符串之间查找字符串

Question

I'm getting a string with some patterns, like:

A 11 A 222222 B 333 A 44444 B 55 A 66666 B

How to get all the strings between A and B in the smallest area?

For example, "A 11 A 222222 B" result in " 222222 "

And the first example should result in:

222222 
333 
44444 
55 
66666

Answer 1

We can try searching for all regex matches in your input string which are situated between A and B , or vice-versa. Here is a regex pattern which uses lookarounds to do this:

(?<=\bA )\d+(?= B\b)|(?<=\bB )\d+(?= A\b)

Sample script:

string input = "A 11 A 222222 B 333 A 44444 B 55 A 66666 B";
var vals = Regex.Matches(input, @"(?<=\bA )\d+(?= B\b)|(?<=\bB )\d+(?= A\b)")
    .Cast<Match>()
    .Select(m => m.Value)
    .ToArray();
foreach (string val in vals)
{
    Console.WriteLine(val);
}

This prints:

222222
333
44444
55
66666