Define a string with single quotation marks?

Question

This is kind of a short question. All I want to know is, if I can define a string using single quotation marks ('), instead of the regular ones("). I want to use it in a function like this: print('Hello world');

I unfortunately do not have an Arduino nearby so I cannot test it myself.

• Gerben: single quotes identify a single character, while double quotes create a string literal
• Edgar Bonet: Could you please explain what you want to achieve rather than your likely misguided idea about how to achieve it (i.e. removing quotes)?
• user29519: I am making an extensions for a program that requires Arduino code inside the program, but if I write the quotation marks, the debugger reports an error, because there are quotation marks inside quotation marks.
• jose can u c: Then you need to update your extension to properly escape the arduino code so that reserved/special characters in the code are not interpreted by the non-arduino debugger. How to do that depends greatly on the program you are extending, which you have not named.
• Mark Smith: It's a bit unclear to me what you're trying to do, but perhaps just escaping the "s will achieve what you want. In C, the way to escape something is with a ,円 so for example char myString[] ="\"\""; would give you a string containing two "s.

Answer 1

No, you can't. 'x' defines a single character or integer (note: 'ab' is a two-byte single value [integer] made up from the ASCII values of both characters).

To include " within a string you have two options:

1. Escape the " with \, as in: char foo[] = "He said \"Hello there\".";
2. Use "raw strings" if the compiler is configured to support it: char foo[] = R"(He said "Hello there".)";

Option 1 is the most portable since it doesn't require compiler support for modern C++ standards. However it's the hardest to read, especially when you get lots of escapes in the same string.

You can make it more readable by defining QUOTE:

#define QUOTE "\""
char foo[] = "He said " QUOTE "Hello there" QUOTE ".";

Answer 2

No, you cannot. This rules comes from the basic C++ syntax on which the Arduino platform is built.

• user29519: Is there a way to define it without the qoutation marks?
• Edgar Bonet: Only very convoluted ways.
• James Waldby - jwpat7: Actually, C++ raw string literals are easy to use (ref 1, 2); the only convoluted bit is adding a -std=c++11 or -std=c++0x switch to IDE compiler options.