using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"@(\""[\w\s]+\"")|(?!@(\w+)@(\w+))@(\w+)";
string input = @"There is @key1 apples on the table.
There is @""key1"" apples on the table.
There is @key 4 apples on the table.
There is @""key 4"" apples on the table.
There is @key@key2 apples on the table.
There is @key3 apples on the table. (second step)
There is @""key @""key3"" apples on the table.
There is @""key 4"" apples on the table. (second step)
There is @""key @key3"" apples on the table.
There is @""key 4"" apples on the table. (second step)
There is @""key @key3 "" apples on the table.
There is @""key 4 "" apples on the table. (second step)
There is @""key @""key3@key7"" apples on the table.
There is @""key @""key32"" apples on the table. (second step)
There is @""key 21"" apples on the table. (3rd step)
There is @key@key2@key3@key4 apples on the table.
There is @key@key2@key35 apples on the table. (second step)
There is @key@key26 apples on the table. (3rd step)
There is @key7 apples on the table. (4th step)
";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx