7 Jul 2004 14:47
using || and && in a more clever way
John Rose made heaps of good suggestions during a face to face at
JavaOne. I'll try brain dump them to the mail lists and/or wiki over
the coming weeks. This one's particularly cute.
x = a || b
would return either the value of a, if its coerced to a boolean and is
true or the value of b. Right now null is false and non null is true.
So if a or b could be null you could use the above to return the non
null value.
A common requirement is if a value is null then use another value. So
we could do
text = customer.name || "unknown"
to grab some text and if its null use some default value.
Similarly if we want to set a variable if its null we could replace
code like this
if (x == null) {
x = "foo"
}
with
x ||= "foo"
We could do similar things for && and &&= as well.
Thoughts?
James
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