There was a time when people thought of computers as manipulating numeric values exclusively. Among the first uses 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 in addition to strings of numbers. Typically, these strings are used for word processing, document manipulation, and the 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 string—that is, to a set of characters. Often, that string is an entire text document. ...