To save some typing and clarify my code, is there a standard version of the following method?
public static boolean bothNullOrEqual(Object x, Object y) {
return ( x == null ? y == null : x.equals(y) );
}
views:
728answers:
6
A:
I know it can be done in VB - http://www.csidata.com/custserv/onlinehelp/VBSdocs/vbs428.htm, it's the EQV operator.
It can be done in Perl, and C++ would view (X==Y) fine if both are NULL.
Based on this page from the Java tutorial from Sun, http://java.sun.com/docs/books/tutorial/java/nutsandbolts/operators.html, it appears to not be possible.
warren
2008-10-08 21:02:45
In what sense is it "not possible"? It's quite possible: the above method is perfectly legal. The question is whether it's implemented in the JDK.
Chris Conway
2008-10-08 21:11:32
I think maybe he's talking about operator overloading?
Michael Myers
2008-10-08 21:12:48
Your C++ example is not equivalent to the Java version. X and Y could be non-null and point to objects with equal content, and (X==Y) would return false.
finnw
2008-10-08 21:38:23
+1
A:
No. I've seen people suggesting putting a similar method in a utility class, but it isn't in the standard library (the Object class seems like a good place, but who am I to suggest it?).
Michael Myers
2008-10-08 21:04:02
+3
A:
if by some chance you are have access to the Jakarta Commons library there is ObjectUtils.equals() and lots of other useful functions.
EDIT: misread the question initially
Matt
2008-10-08 21:10:40
Only if you only ever use the bothNullOrEqual function... what if you use equals directly in one place?
Neil Williams
2008-10-08 22:13:29
It does seem strange that you'd want the same behaviour if two objects were equal OR were both NULL ...
Bobby Jack
2008-10-08 22:16:43
If you are implementing a Collection, your .contains() method, when given "o" needs to test "if this collection contains at least one element e such that (o==null ? e==null : o.equals(e))." Similarly, your .remove() method has to remove such an element.
newacct
2009-07-09 06:16:17
A:
I have this method.
For the sake of saving character calories, its named eq.
Adrian
2008-10-08 22:11:01