The following typographical conventions are used in this book. Italic is used for: -
Directory pathnames and filenames -
Domain names and example URLs -
New terms where they are first defined Constant width is used for: -
Code examples and output -
Names and keywords in C# programs, including method or field names, variable names, and class names -
XML and HTML element tags -
Registry keys Constant width italic is used for: In several parts of this book, we have included simple grammar specifications for many, but not all, of the language constructs introduced in this book, to provide you with a fast way to understand the grammar of a particular construct and its valid combinations. In this grammar syntax, the XML occurrence operators ( ? , * , and + ) are used to specify more precisely the number of times an element may occur in a particular construct: - x
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Indicates x is to be used verbatim ( constant width ) - x
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Indicates x is supplied by the programmer ( constant width italic ) - x?
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Indicates x may occur zero or one times. - x*
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Indicates x may occur zero or more times, separated by commas. - x+
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Indicates x may occur one or more times, separated by commas. - [...]
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Indicates a logical grouping of code elements, when not implicitly grouped using the verbatim terms { } , ( ) , and [ ] . - [xy]
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Indicates only one of a choice of code elements may occur. | This icon designates a note, which is an important aside to the nearby text. | | |