perl not vs. !

hockeyman_102 · 06-12-2009, 03:24 PM

This is retarded, I know, but I got hammered on today by my boss about using 'not' instead of a '!'. Does anyone have any in-depth knowledge on which is faster, better, smarter, etc.?

The snippit is below:

Code:

if(not defined $params{'cookie'}){
     # No cookie?  Give 'em one.
     ...
}

Thanks!

colucix · 06-12-2009, 03:58 PM

A snippet from "Perl in a Nutshell"

Quote:

Unary ! performs logical negation, that is, "not." The not operator is a lower-precedence version of !.

And from the official Perl documentation:

Quote:

Unary "not" returns the logical negation of the expression to its right. It's the equivalent of "!" except for the very low precedence.

GaijinPunch · 06-12-2009, 07:34 PM

It's probably better programming practice to use the universal '!' instead of the unary equivalent to boot. I know I like to remember as little as possible anyway.