The Regex class is used for representing a regular expression. A regular expression is a pattern that could be matched against an input text.
The following are the methods of Regex class −
| Sr.No | Method & Description |
|---|---|
| 1 | public bool IsMatch(string input) Indicates whether the regular expression specified in the Regex constructor finds a match in a specified input string. |
| 2 | public bool IsMatch(string input, int startat) Indicates whether the regular expression specified in the Regex constructor finds a match in the specified input string, beginning at the specified starting position in the string. |
| 3 | public static bool IsMatch(string input, string pattern) Indicates whether the specified regular expression finds a match in the specified input string. |
| 4 | public MatchCollection Matches(string input) Searches the specified input string for all occurrences of a regular expression. |
| 5 | public string Replace(string input, string replacement) In a specified input string, replaces all strings that match a regular expression pattern with a specified replacement string. |
| 6 | public string[] Split(string input) Splits an input string into an array of substrings at the positions defined by a regular expression pattern specified in the Regex constructor. |
The following example use the Matches() method to search the specified input string −
Example
using System;
using System.Text.RegularExpressions;
namespace RegExApplication {
class Program {
private static void showMatch(string text, string expr) {
Console.WriteLine("The Expression: " + expr);
MatchCollection mc = Regex.Matches(text, expr);
foreach (Match m in mc) {
Console.WriteLine(m);
}
}
static void Main(string[] args) {
string str = "make maze and manage to measure it";
Console.WriteLine("Matching words start with 'm' and ends with 'e':");
showMatch(str, @"\bm\S*e\b");
Console.ReadKey();
}
}
}Output
Matching words start with 'm' and ends with 'e': The Expression: \bm\S*e\b make maze manage measure