...
Does this do a shallow copy or a deep copy?
Answer
No copy at all, it just changes the {{ Wiki Markup _refPoint
}} variable to reference the passed in array, and presumably eventually garbage collects the old {{double
\[3
\]
}}. This is not in general a good idea, because the code may not behave the way the caller expects, for example:
Code Block | ||||
---|---|---|---|---|
| ||||
double d = { 1, 2, 3} setReferencePoint(d); d[0] = 3; |
...
or to make sure the documentation to setReferencePoint
explains that it will hold a reference to the array and the user should not modify it.
In fact we generally discourage the use of {{ Wiki Markup double
\[3
\]
}} for momentum or space point. Try using Hep3Vector instead:
http://java.freehep.org/freehep-physics/apidocs/hep/physics/vec/Hep3Vector.html