Reputation: 142
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.
Upvotes: 0
Views: 1308
Reputation: 27250
Did you #include
the header where String
is declared? Maybe this one:
#include <WString.h>
Upvotes: 0
Reputation: 20726
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.
Upvotes: 1