Chapter 15. Strings


There was a time (long, long ago, when the earth was still molten and I was in high school) when people thought of computers as manipulating numeric values exclusively. Among the first use of computers was to calculate missile trajectories during World War II, and for a very long time, programming was taught in the math department of major universities.

Today, most programs are concerned more with manipulating and displaying strings of characters than with strings of numbers . Typically, these strings are used for word processing, document manipulation, and creation of web pages.

C# provides built-in support for a fully functional string type. More importantly, C# treats strings as objects that encapsulate all the manipulation, sorting, and searching methods normally applied to strings of characters.

The .NET Framework provides a String class (uppercase "S"). The C# language offers an alias to the String class as the string class (lowercase "s"). These class names are interchangeable, and you are free to use either upper- or lowercase.


Complex string manipulation and pattern matching is aided by the use of regular expressions .

Regular expressions are a powerful technology for describing and manipulating text. Underlying regular expressions is a technique called pattern matching , which involves comparing one string to another, or comparing a series of wildcards that represent a type of string to a literal string. A regular expression is applied to a stringthat is, to a set of characters. Often, that string is an entire text document. More on regular expressions later in this chapter.


C# combines the power and complexity of regular expression syntax, originally found only in string manipulation languages such as awk and Perl, with a fully object-oriented design.

In this chapter, you will learn to work with the C# string type and the .NET Framework System.String class that it aliases. You will see how to extract sub-strings , manipulate and concatenate strings, and build new strings with the StringBuilder class. In addition, you will find a short introduction to the RegEx class used to match strings based on regular expressions.



Learning C# 2005
Learning C# 2005: Get Started with C# 2.0 and .NET Programming (2nd Edition)
ISBN: 0596102097
EAN: 2147483647
Year: 2004
Pages: 250

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net