logical AND "&&"

odegbon has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: logical AND "&&" by toolic (Bishop) on Jan 31, 2010 at 02:00 UTC
Yes, you can. If you can't remember Operator Precedence and Associativity, then just add more parentheses so that there is no doubt. `if ( (($a == 1) && ($b < 2)) && (($d < 4) && ($e >= 6)) ){ do somethin +g ...` [download] The and operator can also be used in place of &&. and has lower precedence, but the following is the same as the above: `if ( (($a == 1) and ($b < 2)) and (($d < 4) and ($e >= 6)) ){ do somet +hing ...` [download]	[reply] [d/l] [select]
Re^2: logical AND "&&" by odegbon (Initiate) on Jan 31, 2010 at 02:13 UTC
Thanks, Toolic	[reply]
Re: logical AND "&&" by Corion (Patriarch) on Jan 30, 2010 at 23:29 UTC
What happened when you tried?	[reply]
Re: logical AND "&&" by YuckFoo (Abbot) on Jan 30, 2010 at 23:32 UTC
No, you may not. `#!/usr/bin/perl use strict; my ($a, $b, $d, $e) = (1, 1, 1, 7); if(($a == 1 && $b < 2) && ($d < 4 && $e >= 6)) { print "Trying is fun!\n" };` [download]	[reply] [d/l]
Re^2: logical AND "&&" by odegbon (Initiate) on Jan 30, 2010 at 23:42 UTC
Hi YuckFoo, did you say I may not? But I ran your code and it worked	[reply]
Re^3: logical AND "&&" by YuckFoo (Abbot) on Jan 30, 2010 at 23:59 UTC
My bad, go ahead and do it. There is much iffing and anding to be done! Code coder, code!	[reply]
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Re: logical AND "&&" by ikegami (Patriarch) on Jan 31, 2010 at 17:05 UTC
In fact, `if (($a == 1 && $b < 2) && ($d < 4 && $e >= 6)) {` [download] could be written as `if ($a == 1 && $b < 2 && $d < 4 && $e >= 6) {` [download]	[reply] [d/l] [select]
Re^2: logical AND "&&" by Anonymous Monk on Jan 31, 2010 at 17:14 UTC
I heard you could write `if($a==1&&$b<2&&$d<4&&$e>=6){` [download]	[reply] [d/l]
Re^3: logical AND "&&" by ikegami (Patriarch) on Jan 31, 2010 at 17:25 UTC
It wasn't clear if he knew the parens weren't necessary. Also, it wasn't clear if he knew that `if (($a == 1 && $b < 2) && ($d < 4 && $e >= 6)) {` [download] is the same as `if ($a == 1 && ($b < 2 && ($d < 4 && ($e >= 6))) {` [download] Those are the two things I pointed out in my post. I wasn't trying to say that parens are bad. In this case, though, spacing can also provide clear disambiguation `if ($a==1 && $b<2 && $d<4 && $e>=6) {` [download]	[reply] [d/l] [select]