slash character in char array

Using Arduino Programming Questions
#1

Hi,
I have a silly question. I need to initialize a char array with something like

char myarray[2]={'','r'};

but I have some problem with this code since when I try to compile I have an error

Exception in thread "Thread=10" java.lang.StackOverflowError

I think that \ represent some special character in the IDE...how can I transform the slash to a "pure" character (not sure how to say it...)?

thanks!

#2 
char myarray[2]={'\\','r'};

Or did you mean simply '\r' ?

#3

actually it should be

char myarray[2]={'\\','r'};

but also in this way the compiler gives me the same error :frowning:

#4

The error comes from the preprocessor - usually the comment stripping routines.

That line as it stands does not cause an error - you should check the rest of your code, especially your comments.

#5

Use the decimal value of the ASCII for the characters you wish:

char myarray[2]={92,114};
#6

I am sure the error comes from the '\' because if I remove it I do not have compilation problems.

The decimals should work....but I guess that I can not make a composite array of characters and decimals like

char myarray[2]={92,'r'};

right?

how do I specify that the 92 is decimal or that myarray is coded with decimals?

#7

I guess that I can not make a composite array of characters and decimals like

Why would you guess that? Try it and see.

#8

Everything is a number. Internally stored as 8-bit values (0-255). Everything else is purely a human interpretation of those 8 bits, including 'r'.

I suggest you post your entire code so we can replicate the error. We cannot replicate the error from just that one line.

#9

It actually worked with the mixed dec and char :slight_smile:

char mystring[2]={92,'r'};

Thanks guys that helped!!!

#10

You know of course that what you have now is not nul-terminated, and cannot be used in str*() functions that accept a string.

You could also use:

char mystring[2] = "\\r";
#11

KeithRB:
You know of course that what you have now is not nul-terminated, and cannot be used in str*() functions that accept a string.

You could also use:

char mystring[2] = "\\r";

... except the strn* functions that take a length parameter :stuck_out_tongue:

#12

actually I can still create the array with the last character being the end of line:

char mystring[3]={92,'r','\n'};

and this works too :slight_smile:

#13

Except you still have no terminating character (line feed isn't end of string - character 0 is):

char mystring[4]={92,'r','\n', 0};
#14

While we are nitpicking, it might be germane to point out that the character '' is apparently most clearly called the backslash character, not the slash character, which is '/' .

#15

AWOL:

char myarray[2]={'\\','r'};

Or did you mean simply '\r' ?

To me this is really good question.
That and is the array supposed to be a character array or a C string?

In other words:

  1. is this supposed to be a 2 character array or a C string?
  2. is this supposed to contain backslash and a r or a carriage return?

--- bill

#16