Re: Question about ternary operator

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Re^2: Question about ternary operator by merlinX (Novice) on Jul 01, 2009 at 08:42 UTC
Thx, operator precedence is sometimes a PITA, so this is what the first ternary statement should look like then `exists($checked->{Group}{$GroupDN}) ? ($rc_OK=1) : ($rc_OK=check_group +($GroupDN,0));` [download]	[reply] [d/l]
Re^3: Question about ternary operator by moritz (Cardinal) on Jul 01, 2009 at 08:52 UTC
No, it should look exactly like the first statement. The ternary operator is very good if you use its value, but if you use it in void context it's just a kludge for an `if` statement. So `# bad: ternary in void context: exists($checked->{Group}{$GroupDN}) ? ($rc_OK=1) : ($rc_OK=check_group +($GroupDN,0)); # good: 'if' in void context: if (exists($checked->{Group}{$GroupDN})) { $rc_OK = 1 } else { $rc_OK=check_group($GroupDN,0) } # also good: ternary in scalar context: $rc_OK = exists($checked->{Group}{$GroupDN}) ? 1 : check_group($Group +DN,0)` [download] So you have two good, idiomatic ways to express something, and complain that the third is a PITA?	[reply] [d/l] [select]
Re^3: Question about ternary operator by ikegami (Patriarch) on Jul 01, 2009 at 18:31 UTC
Thx, operator precedence is sometimes a PITA If the precedence was reversed, the intended use would not work. `$y = $c ? $x1 : $x2;` [download] would mean `($y = $c) ? $x1 : $x2;` [download] By the way, it's called the "conditional operator". Perl has many ternary operators.	[reply] [d/l] [select]
Re^4: Question about ternary operator by Anonymous Monk on Jul 01, 2009 at 18:38 UTC
Perl has many ternary operators. Really? There are none listed in perlop or http://en.wikipedia.org/wiki/%3F:/http://en.wikipedia.org/wiki/Ternary_operation	[reply]
Re^5: Question about ternary operator by ikegami (Patriarch) on Jul 01, 2009 at 19:02 UTC
Re^2: Question about ternary operator by rovf (Priest) on Jul 01, 2009 at 11:50 UTC
The problem is that the assignment has a looser precedence than the ternary op. Shouldn't then the OP's program had reported a syntax error? -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]
Re^3: Question about ternary operator by moritz (Cardinal) on Jul 01, 2009 at 11:54 UTC
No: `$ perl -MO=Deparse,-p -e '1 ? $a = 3 : $b = 4' (($a = 3) = 4); -e syntax OK` [download] You see it is parsed, not just the way you'd naively expect it.	[reply] [d/l]