I have a basic question.
I have a class with a data member : double _mydata[N]
. (N is a template parameter).
What is the syntax to initialize these data to zero
No, prior to C++11 you need to do just this to default-initialise each element of the array:
: _mydata()
The way you have it written won't work.
With C++11 it is more recommended use uniform initialisation syntax:
: _mydata { }
And that way you can actually put things into the array which you couldn't before:
: _mydata { 1, 2, 3 }