Kyle Wayne Kelly
(504)391-3985
http://www.cs.uno.edu/~kkelly
----- Original Message -----
From: "William Kaufman" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, August 09, 2001 7:14 AM
Subject: RE: Using Tomcat with MSAccess
> > <snip />
> > > > "".equals(passwd)
> > > > rather than
> > > > passwd.equals( "" )
> > <snip />
> > > No you shouldn't. That's totally evil. For a start, you're
> > > creating another String object by doing ""
> > <snip/>
> > <remark>
> > As "" is a constant string, it is created just once. So there
> > is not much overhead.
>
> True, other than the overhead of calling String.intern() when the class is
> loaded (JLS 3.10.5).
>
> > ("".equals might be even faster, because
> > the jit can inline the method call, as the address of the object
> > and the equals method is constant in this case.
>
> False. If the compiler can inline equals(), it can inline length(), too.
> (In fact, it's more likely to inline length(), since it's a far simpler
> method.)
I wonder if equals() is implemented with a bitwise "and". If that were the
case, then the first invocation of equals would be simpler than the length
method (that is with delayed lazy evaluation).
>
> (And take a look at the source for String.equals(): at best, with
comparable
> inlining of the two methods, you've added an "instanceof" and a downcast,
> which likely swamps any time taken for the rest of the comparison.)
>
> -- Bill K.
