Is there a good reason why there is no Pair<L,R>
in Java? What would be the equivalent of this C++ construct? I would rather avoid reimplementing my own.
It seems that 1.6 is providing something similar (AbstractMap.SimpleEntry<K,V>
), but this looks quite convoluted.
In a thread on comp.lang.java.help
, Hunter Gratzner gives some arguments against the presence of a Pair
construct in Java. The main argument is that a class Pair
doesn't convey any semantics about the relationship between the two values (how do you know what "first" and "second" mean ?).
A better practice is to write a very simple class, like the one Mike proposed, for each application you would have made of the Pair
class. Map.Entry
is an example of a pair that carry its meaning in its name.
To sum up, in my opinion it is better to have a class Position(x,y)
, a class Range(begin,end)
and a class Entry(key,value)
rather than a generic Pair(first,second)
that doesn't tell me anything about what it's supposed to do.