Is Verbatim or escaping the preferred way to deal with quote-rich strings in C#?

Question

To escape or to verbatim, that is my question.

I need to programmatically send a couple of commands to a (Zebra QLn220) printer in C#, specifically:

! U1 setvar "power.dtr_power_off" "off"

-and:

! U1 setvar "media.sense_mode" "gap"

Due to the plethora of quotes in these commands, I thought it would be sensible to use verbatim strings. But based on this, I still need to double the quotes, so that it would presumably/theoretically need to be like:

string dontShutErOff = @"! U1 setvar """power.dtr_power_off""" """off"""";

...which looks like a mashup composed of Don King, the cat from Coding Horror, and Groucho Marx.

Would it be better to escape the quotes this way:

string dontShutErOff = "! U1 setvar \"power.dtr_power_off\" \"off\"";

?

Should I Escape from Verbatimtraz?

UPDATE

Based on Eric Lippert's first suggestion, how about this:

const string quote = "\"";
string whatever = string.Format("! U1 setvar {0}power.dtr_power_off{0} {0}off{0}", quote);

Escaping correctly is more important: in verbatim, `""`, not `"""`, is the escaped version of `"`. — Tim S., Apr 18 '14 at 17:12
2 upvotes and 3 close votes; that seems an odd juxtaposition — B. Clay Shannon-B. Crow Raven, Apr 21 '14 at 16:59
I suggested a [feature](https://roslyn.codeplex.com/workitem/62) to deal with usecases like this. I don't think any of the current methods are satisfactory. — MgSam, Apr 21 '14 at 20:57

score 5 · Answer 1 · answered Apr 18 '14 at 16:46

5

Resources may be better approach - it looks like you planning to have C# constants to have names anyway.Let resource auto-generation to create C# constant for you while editing commands as regular text.

answered Apr 18 '14 at 16:46

Alexei Levenkov

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If I had a bunch of these, I guess; but for just two, using resource strings seems like putting on a tie to tie your tennies. – B. Clay Shannon-B. Crow Raven Apr 18 '14 at 17:42

score 5 · Accepted Answer · answered Apr 18 '14 at 18:11

5

I would consider a third alternative:

const string quote = "\"";
string whatever = "! U1 setvar " + 
                  quote + "power.dtr_power_off" + quote + " " +
                  quote + "off" + quote;

Or a fourth:

static string Quote(string x) 
{
    const string quote = "\""; 
    return quote + x + quote;
}
...
string whatever = "! U1 setvar " + Quote("power.dtr_power_off") + " " + Quote("off");

All these have pros and cons; none is clearly the best.

answered Apr 18 '14 at 18:11

Eric Lippert

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What is the reason for putting `const` on the `quote` variable? I can see it's generating different IL codes then a non-const string variable, but I'm not sure why or what the difference is. – asawyer Apr 18 '14 at 18:41
What do you think about my take on your first take (in my Update above)? – B. Clay Shannon-B. Crow Raven Apr 18 '14 at 18:52
4

@asawyer Making the variable `const` means that the compiler will do a straight in-source substitution, at which point the compiler's constant-folding logic will ensure that the final string is completely formed at compile-time, rather than forcing run-time concatenation. – dlev Apr 18 '14 at 19:27

Scampbell · Answer 3 · 2014-04-18T16:54:21.153

2

Verbatim strings don't allow double quotes as you've described in your first example. It won't compile.

I juts found this out actually... It does support double-double quotes as quotes. So your first example would look like this:

string dontShutErOff = @"! U1 setvar ""power.dtr_power_off"" ""off""";

However, if your string literals are important, won't likely change, or may need to be translated in the future, I would put them in a resource file as mentioned in a previous answer. Any escaping is done automatically and the string is easily readable.

edited Apr 18 '14 at 16:54

answered Apr 18 '14 at 16:46

Scampbell

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Thanks; BTW, is your name Scot Campbell, or Scamp Bell? – B. Clay Shannon-B. Crow Raven Apr 18 '14 at 17:04
1

No problem. Stack Overflow users have profile sections with names and other information like that. You're closer on the first one though :) – Scampbell Apr 18 '14 at 17:24
Your profile simply says "Scampbell," so...it *is* a problem ;-) – B. Clay Shannon-B. Crow Raven Apr 18 '14 at 17:40
Good to know. I thought all of that was public. It's Sam Campbell. – Scampbell Apr 18 '14 at 17:45

score 1 · Answer 4 · answered Apr 18 '14 at 16:55

Your first line should be:

string dontShutErOff = @"! U1 setvar ""power.dtr_power_off"" ""off""";

Quotation marks are written as double quotation marks, not triple.

Neither way is clearly better than the other, at least not for quotation marks. It's mostly a matter of taste. In other situations one way or the other has clear advantages, for example using a @ delimited string for file paths that contain backslashes.

Is Verbatim or escaping the preferred way to deal with quote-rich strings in C#?

UPDATE

4 Answers4