Reserved Word - Reserved Words and Language Independence

Reserved Words and Language Independence

Microsoft’s .NET Common Language Infrastructure (CLI) specification allows code written in 40+ different programming languages to be combined together into a final product. Because of this, identifier/reserved word collisions can occur when code implemented in one language tries to execute code written in another language. For example, a Visual Basic.NET library may contain a class definition such as:

' Class Definition of This in Visual Basic.NET: Public Class this ' This class does something... End Class

If this is compiled and distributed as part of a toolbox, a C# programmer, wishing to define a variable of type “this” would encounter a problem: 'this' is a reserved word in C#. Thus, the following will not compile in C#:

// Using This Class in C#: this x = new this; // Won't compile!

A similar issue arises when accessing members, overriding virtual methods, and identifying namespaces.

In order to work around this issue, the specification allows the programmer to (in C#) place the at-sign before the identifier which forces it to be considered an identifier rather than a reserved word by the compiler.

// Using This Class in C#: @this x = new @this; // Will compile!

For consistency, this usage is also permitted in non-public settings such as local variables, parameter names, and private members.

Read more about this topic:  Reserved Word

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    “This is that which we call Character,—a reserved force which acts directly by presence, and without means.”
    —Ralph Waldo Emerson (1803–1882)

    “If the sea were ink
    For the words of my Lord,
    the sea would be spent before the Words of my Lord are spent.”
    —Qur’An. The Cave 18:109, ed. Arthur J. Arberry (1955)

    “It would seem as if the very language of our parlors would lose all its nerve and degenerate into palaver wholly, our lives pass at such remoteness from its symbols, and its metaphors and tropes are necessarily so far fetched.”
    —Henry David Thoreau (1817–1862)

    “It is my duty to prevent, through the independence of Cuba, the U.S.A. from spreading over the West Indies and falling with added weight upon other lands of Our America. All I have done up to now and shall do hereafter is to that end.... I know the Monster, because I have lived in its lair—and my weapon is only the slingshot of David.”
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