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Principals A principal performs an action for a user. Principals are authenti-
cated using credentials supplied by the principal agent. .NET ensures that code
only completes actions that it is authorized to perform.
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Type-safety C# provides optional type-safety, which ensures that code may
only have access to authorized memory locations.
C#’s Hello, World!
“Hello, World!” is the simplest program to use for accomplishing a task. Beginning pro-
grammers learn “Hello, World!” to develop an understanding of the basic structure of
the language, as well as to learn how to use a compiler and run a program.The fol-
lowing is an example of “Hello, World!”