Solution to Question 15-1.
string (lowercase) is the C# keyword that maps to the .NET Framework
String class. They may be used interchangeably.
Solution to Question 15-2.
IComparable guarantees that strings can be sorted.
ICloneable guarantees that you can call the
Clone method on a string object and get back a new duplicate string.
IConvertible allows strings to be converted to other types (such as integers). And
IEnumerable guarantees that strings can be iterated over in
Solution to Question 15-3. A string literal is a quoted string, provided by the programmer, such as “Hello”.
Solution to Question 15-4. An escape character embedded in a string indicates that the character or punctuation that follows is to be treated as an instruction rather than as part of the string.
\n indicates a new line.
\" indicates that the quote symbol is part of the string, not terminating it.
Solution to Question 15-5. Verbatim strings are taken “as is” and thus do not require escape characters. Where
\\ would indicate a single backslash in a normal string, in a verbatim string it indicates two backslashes. Verbatim strings must include an
@ character before the first double quote.
Solution to Question 15-6. The fact that strings are immutable means they cannot be changed. When you appear to change a string, what actually happens is that a new string is created and the old string is destroyed by the garbage collector if it is no longer referenced.