Complete set: Intro to C - Bill Buchanan

5.11 Regular Expressions
Use of regular expressions can simplify much of the hard work of string processing.
We can specify patterns that get matched against input strings.
Some simple patterns:
Simple Patterns
.
Matches any character
\s
Matches any white space character
\S
Matches any non white space characters
\d
Matches any digit
and
Matches the word and
.*
Matches any number of any characters – "greedy" match
^
Matches the beginning of the search string
$
Matches the end of the search string
duction to .NET
Intro
Because we make use of the \ character regular expressions are almost always defined
using @ʺ.
Simple Patterns
Regex re = new Regex(@"^B.*land");
StreamReader sr = new StreamReader(@"..\..\ciaTabbed.txt");
while (sr.Peek()>0)
{
string s = sr.ReadLine();
if (re.Match(s).Success)
Console.WriteLine(s);
}
The above section of code searches for strings that start with B and include ʺlandʺ
Matches for ^B.*land
Baker Island Oceania 1.4 0
Bouvet Island Antarctic Region 58.5 0
British Virgin Islands Central America and the Caribbean 150 19615 287000000
5.11.1 Extracting substrings using Regular Expressions
We can include brackets in our patterns and obtain the contents of these.
Agilent .NET Course: Module 5, page 9