This article I will discuss about regular expression (or RegEx in short) class in .Net
Regular Expression is a big topic and cannot be covered in a single article. I tried to explain it in brief.
In dot net there is a strong support for regular expression class. A regular expression is a string that is used to describe match based on certain rule. Regular expression is a very powerful tool for pattern matching.
Regular Expression can be found in System.Text.RegularExpressions namespace.
Example for using regular expression:
if (Regex.IsMatch("ASP.Net", "ASP"))
{
MessageBox.Show("match");
}
else
{
MessageBox.Show("no match");
}
Above example ("where "ASP" is a pattern") search for the matching world "ASP" in the string "ASP.Net", if match found, shows message "match".
Similar way different pattern can be passed for searching a particular string.
Note: Regular Expression is a case sensitive; "a" is different from "A".
Example:
|
String |
Pattern |
Result |
|
Sales001 |
Sale. |
True |
|
Sal123 |
Sale. |
False |
|
Sale.xls |
Sale. |
True |
|
Sale.xls |
sale. |
False |
|
Sale |
.a. |
True |
Some of the list of patterns.
|
Pattern |
Matches |
|
*. |
Searches any string |
|
Sales$ |
Searches string which ends with "Sales"
Example : Sales, finale Sales, year 2007 Sales |
|
^v[i,v]k$ |
vik, vvk (string starts with v and ends with k and contains i and v) |