Undeclared string in Arduino class

Question

I am trying to write a class for an Arduino library. I am having a hard time getting it to allow me to pass a string variable to a method within the class.

I keep getting:

...Calc.h:21: error: 'String' has not been declared

Referring to this line of code which is line 21 in Calc.h:

void printCalc(int a, int b, String s);

I don't understand why it says that it has not been declared, because there are no problems with my int's. and I didn't do anything different with them.

Jim Buck · Accepted Answer · 2011-12-16 23:24:18Z

1

You need to #include the header file that defines String before calc.h. calc.h should be the one to #include the header where String lives, but I see this mistake quite a bit with library developers.

answered Dec 16, 2011 at 23:24

Jim Buck

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Igor · Accepted Answer · 2011-12-16 23:29:27Z

0

Did you #include the header where String is declared? Maybe this one:

#include <WString.h>

edited Dec 16, 2011 at 23:29

answered Dec 16, 2011 at 23:20

Igor

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