RE: Testing Uninitialized Vars

2003-10-02 Thread TN
>if (defined $x and length $x) > >So, is this the opposite? > >if (! defined $x and ! length $x) I don't think so. It's basic Aristotelian logic and can be determined by truth tables or testing. Questions are mere conjecture :) The negative of a statement, A, is: not A. That can be writte

Re: Testing Uninitialized Vars

2003-10-02 Thread Steve Grazzini
On Thu, Oct 02, 2003 at 07:41:41PM -0700, [EMAIL PROTECTED] wrote: > unless understood, how about this. > > if (defined $x and length $x) > > So, is this the opposite? > > if (! defined $x and ! length $x) Nope; now you've got a boolean logic problem. Either of these would work, but unless() is

Re: Testing Uninitialized Vars

2003-10-02 Thread perl
unless understood, how about this. if (defined $x and length $x) So, is this the opposite? if (! defined $x and ! length $x) -rkl > On Thu, Oct 02, 2003 at 07:03:02PM -0700, [EMAIL PROTECTED] wrote: >> > if (defined $x and length $x) >> >> So, is this the opposite? >> >> if (! defined $x and

Re: Testing Uninitialized Vars

2003-10-02 Thread Steve Grazzini
On Thu, Oct 02, 2003 at 07:03:02PM -0700, [EMAIL PROTECTED] wrote: > > if (defined $x and length $x) > > So, is this the opposite? > > if (! defined $x and length $x) Nope; you've got a precedence problem. unless( defined $x and length $x ) { } -- Steve -- To unsubscribe, e-mail: [EMAIL

RE: Testing Uninitialized Vars

2003-10-02 Thread perl
> if (defined $x and length $x) So, is this the opposite? if (! defined $x and length $x) or do I have to parenthesis if (! (defined $x and length $x)) -rkl > On Oct 2, [EMAIL PROTECTED] said: > >>To recap, I want to test if a var is undefined or ''. >> >> if(undefined $x && length($x)==0) >

RE: Testing Uninitialized Vars

2003-10-02 Thread Jeff 'japhy' Pinyan
On Oct 2, [EMAIL PROTECTED] said: >To recap, I want to test if a var is undefined or ''. > > if(undefined $x && length($x)==0) There IS no 'undefined' function in Perl, and you don't want to use &&, you'd want to use ||, since the empty string "" IS defined. if (not defined($x) or length($x) =

RE: Testing Uninitialized Vars

2003-10-02 Thread perl
t; -Original Message- >> From: James Edward Gray II [mailto:[EMAIL PROTECTED] >> Sent: Thursday, October 02, 2003 5:20 PM >> To: [EMAIL PROTECTED] >> Cc: [EMAIL PROTECTED] >> Subject: Re: Testing Uninitialized Vars >> >> >> On Thursday, Octob

Re: Testing Uninitialized Vars

2003-10-02 Thread James Edward Gray II
On Thursday, October 2, 2003, at 07:23 PM, LoBue, Mark wrote: -Original Message- From: James Edward Gray II [mailto:[EMAIL PROTECTED] Sent: Thursday, October 02, 2003 5:20 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: Testing Uninitialized Vars On Thursday, October 2, 2003

RE: Testing Uninitialized Vars

2003-10-02 Thread LoBue, Mark
> -Original Message- > From: James Edward Gray II [mailto:[EMAIL PROTECTED] > Sent: Thursday, October 02, 2003 5:20 PM > To: [EMAIL PROTECTED] > Cc: [EMAIL PROTECTED] > Subject: Re: Testing Uninitialized Vars > > > On Thursday, October 2, 2003, at 07:08

Re: Testing Uninitialized Vars

2003-10-02 Thread James Edward Gray II
On Thursday, October 2, 2003, at 07:08 PM, [EMAIL PROTECTED] wrote: you mean $x=0; would be false? Yep. James -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]

Re: Testing Uninitialized Vars

2003-10-02 Thread perl
you mean $x=0; would be false? > On Thursday, October 2, 2003, at 06:29 PM, [EMAIL PROTECTED] wrote: > >> Are you saying this would do everything that I want? >> >> #I'm considering undefined var and '' and 0s are the same thing. >> if($x) ... true - do_something > > I said it would, if you don't

Re: Testing Uninitialized Vars

2003-10-02 Thread James Edward Gray II
On Thursday, October 2, 2003, at 06:29 PM, [EMAIL PROTECTED] wrote: Are you saying this would do everything that I want? #I'm considering undefined var and '' and 0s are the same thing. if($x) ... true - do_something I said it would, if you don't mind 0 being false. James -- To unsubscribe, e-

Re: Testing Uninitialized Vars

2003-10-02 Thread perl
Are you saying this would do everything that I want? #I'm considering undefined var and '' and 0s are the same thing. if($x) ... true - do_something -rkl > On Thursday, October 2, 2003, at 05:09 PM, [EMAIL PROTECTED] wrote: > >>> if ( ! defined $x ) >> >> I read up on defined and undefined. But

Re: Testing Uninitialized Vars

2003-10-02 Thread James Edward Gray II
On Thursday, October 2, 2003, at 05:09 PM, [EMAIL PROTECTED] wrote: if ( ! defined $x ) I read up on defined and undefined. But I'm looking for a test that will this return true or false to a var condition: perldoc -f defined perldoc -f undef The second is a little different than what you thin

Re: Testing Uninitialized Vars

2003-10-02 Thread perl
> if ( ! defined $x ) I read up on defined and undefined. But I'm looking for a test that will this return true or false to a var condition: ... sub isNULL { return undefined $_[0] && $_[0] eq '' $_[0] eq ""; } # my goal is all three return the same as # my proposed sub isNULL() my $x;

Re: Testing Uninitialized Vars

2003-10-02 Thread James Edward Gray II
On Thursday, October 2, 2003, at 04:25 PM, [EMAIL PROTECTED] wrote: I wan to write a sub return true or false if the var was initialized. We can do that, but I really don't think we need a sub for it, since there is a built-in. Can someone correct this sub or is it good? No, I wouldn't call it

Testing Uninitialized Vars

2003-10-02 Thread perl
I wan to write a sub return true or false if the var was initialized. Can someone correct this sub or is it good? ... if(isNULL($x) { print "it is null\n"); else { print "it is NOT null\n"); ... sub isNULL { return $_[0] =~ // } thanks, -rkl -- To unsubscribe, e-mail: [EMAIL PR