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POUnusual Regex behavior in c#
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copied!<p>I have a Regex that is behaving rather oddly and I can't figure why. Original Regex:</p> <pre><code>Regex regex = new Regex(@"(?i)\d\.\d\dv"); </code></pre> <p>This expression returns/matches an equivalent to 1.35V or 1.35v, which is what I want. However, it is not exclusive enough for my program and it returns some strings I don't need.</p> <p>Modified Regex:</p> <pre><code>Regex rgx = new Regex(@"(?i)\d\.\d\dv\s"); </code></pre> <p>Simply by adding '\s' to the expression, it matches/returns DDR3, which is not at all what I want. I'm guessing some sort of inversion is occurring, but I don't understand why and I can't seem to find a reference to explain it. All I wanted to do was add a space to the end of expression to filter a few more results.</p> <p>Any help would be greatly appreciated.</p> <p>EDIT: Here is a functional test case with a generic version of what is going on in my code. Just open a new WPF in Visual Studio, copy and paste, and it should repeat the results for you.</p> <pre><code>namespace WpfApplication1 { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); } Regex rgx1 = new Regex(@"(?i)\d\.\d\dv"); Regex rgx2 = new Regex(@"(?i)\d\.\d\dv\s"); string testCase = @"DDR3 Vdd | | | | | 1.35v |"; string str = null; public void IsMatch(string input) { Match rgx1Match = rgx1.Match(input); if (rgx1Match.Success) { GetInfo(input); } } public void GetInfo(string input) { Match rgx1Match = rgx1.Match(input); Match rgx2Match = rgx2.Match(input); string[] tempArray = input.Split(); int index = 0; if (rgx1Match.Success) { index = GetMatchIndex(rgx1, tempArray); str = tempArray[index].Trim(); global::System.Windows.Forms.MessageBox.Show("First expression match: " + str); } if (rgx2Match.Success) { index = GetMatchIndex(rgx2, tempArray); str = tempArray[index].Trim(); System.Windows.Forms.MessageBox.Show(input); global::System.Windows.Forms.MessageBox.Show("Second expression match: " + str); } } public int GetMatchIndex(Regex expression, string[] input) { int index = 0; for (int i = 0; i < input.Length; i++) { if (index < 1) { Match rgxMatch = expression.Match(input[i]); if (rgxMatch.Success) { index = i; } } } return index; } private void button1_Click(object sender, RoutedEventArgs e) { string line; IsMatch(testCase); } } </code></pre> <p>}</p> <p>The GetMatchesIndex method is called a number of times in other parts of the code without incident, it is just on this one Regex that I've hit a stumbling block.</p>

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