C# 3.0 Cookbook, 3rd Edition

Chapter 2. Strings and Characters

2.0. Introduction

String usage abounds in just about all types of applications. The System.String type is a reference type, unlike System.Char, which is a value type and therefore derives from System.ValueType. The string alias is built into C# and can be used instead of the full name.

The Framework Class Library (FCL) does not stop with just the String class; there is also a System.Text.StringBuilder class for performing string manipulations and the System.Text.RegularExpressions namespace for searching strings. This chapter will cover the String class, the System.Text.StringBuilder class, and the Char structure.

The System.Text.StringBuilder class provides an easy, performance-friendly method of manipulating string objects. Even though this class duplicates much of the functionality of a String class, the StringBuilder class is fundamentally different in that the string contained within the StringBuilder object can actually be modified—you cannot modify a string object. However, this duplicated functionality provides a more efficient manipulation of strings than is obtainable by using the String class.

2.1. Determining the Kind of Character a Char Contains

Problem

You have a variable of type char and wish to determine the kind of character it contains—a letter, digit, number, punctuation character, control character, separator character, symbol, whitespace, or surrogate character (i.e., Unicode characters with a value greater than 64K). Similarly, you ...