Learning C# 3.0

The Regex Class

The .NET Framework provides an object-oriented approach to regular expression pattern matching and replacement.

The Framework Class Library (FCL) namespace System.Text.RegularExpressions is the home to all the .NET Framework objects associated with regular expressions. The central class for regular expression support is Regex, which provides methods and properties for working with regular expressions, the most important of which are shown in Table 15-3.

Table 15-3. Regex members

Method or property	Explanation
Regex constructor	Overloaded; creates an instance of Regex
Options	Property that returns the options passed in to the constructor
IsMatch	Method that indicates whether a match is found in the input string
Match	Searches an input string and returns a match for a regular expression
Matches	Searches an input string and returns all successful matches for a regular expression
Replace	Replaces all occurrences of a pattern with a replacement string
Split	Splits an input string into an array of substrings based on a regular expression

Example 15-9 rewrites Example 15-8 to use regular expressions and thus to solve the problem of searching for more than one type of delimiter.

Example 15-9. Regular expressions are indispensable for matching patterns in text

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace Example_15_9_  _  _  _Regular_Expressions
{
    class Tester
    {
        public void Run( ) { string s1 = "One,Two,Three ...