Verbatim string literals v escape sequences

问题:

Is there any difference in how the C# compiler or .NET run-time handles verbatim string literals versus using escape sequences (i.e. performance) or is it just a matter of design time style? E.G.:

var pathA = "c:\\somewhere";
var pathB = @"c:\somewhere";

I would imagine they are compiled the same and it doesn't matter, but was just curious.

回答1:

Any difference here is limited strictly to the compiler; the IL and runtime have no concept of verbatim vs escaped - it just has the string.

As for which to choose: whichever is more convenient ;p I almost always use verbatim string literals if there are unusual characters, as that allows for multi-line strings very easily and visually.

As an interesting case:

bool areSame = ReferenceEquals("c:\\somewhere", @"c:\somewhere"); // true

which tells are they are exactly the same string instance (thanks to "interning"). They aren't just equivalent; they are the same string instance to the runtime. It is therefore impossible that they can be (to the runtime) different in any way.

回答2:

They are exactly the same. Try to decompile the two versions with a decompiler.

It's only a matter of convenience for developers when writing it in the code.

回答3:

The @ sign in front of a string tells the compiler to ignore any embeded escape sequences.

string "\"" would yield a single double quote. string "\" would yield a single back slash string @"\" would yield two backslashes