Re: [PHP4BETA] broken or probably not implement!

On Fri, 18 Feb 2000, Faisal Nasim wrote: > : I'm not sure what you're saying here, all of the results reported by PHP > : are correct. 10||1 is true (boolean). The fact that Perl reports 10 is > > Then why: > > $str = 10 or 1 // = 10 This is equivalent to: $str=10; 10 or 1; Assuming you regard the 'result' as the value of $str, the value of $str is 10. > and > $str = 0 or 1 // = 0 $str=0; 0 or 1; The value of $str is 0. Generally, $str = n or 1;, would always end up with $str being equal to n. > > 0 is false, and 'or' has low precedence, so result should be 1! > Also: > $str = 0 || 1 // = 0 No, ($str = 0 || 1) equals 1: print ($str=0 or 1); 1 Perhaps you tried print $str=0 or 1; in which case, it behaved like this: $str=0; // expr=0 print 0; // prints '0', expr=1 1 or 1; // expr=1, no side effects (i.e. nothing is printed out). Remember, or has very low precedence, its even less than print/echo. I don't have time to dive into the various examples you've given, but I know that this works quite well, so I'm just trying to explain the rules... Zeev > > > $str = "" or "faisal"; // "" > > In Perl, it will behave as a conditional operator and won't return > the boolean match: > > $str = "" || "faisal"; // faisal > $str = "" or "faisal"; // "" > > > BITWISE: > > print "" | "faisal"; // "" > print 10 | 100; // 110 > > > All I was trying to simplify this: > > $str = (int) $blah; > if ( ! $str ) $str = 0; > > Perl: $str = int $blah || 0; > PHP: $str = (int) $blah ? $blah : 0; > > > OR: > > > $total = somelongfunction ( $arg ); > if ( ! $total ) $total = 100; > > Because this will be silly to call our *long* function twice like this: > $total = somelongfunction ( $arg ) ? somelongfunction ( $arg ) : 100; > > Where, in Perl I can: > $total = &somelongfunction || 100; # not returning boolean value! > > > : meaningless, any value that translates into true is valid. If you want to > : conduct bitwise operations, you should be using the bitwise operators, > : i.e. 10|1. > : > : > : Zeev > : > : On Fri, 18 Feb 2000, Faisal Nasim wrote: > : > : > Greetings, > : > > : > PHP could use some more flexibility and some bug fixing! > : > > : > $str = 10 || 1; // 1 > : > $str = 0 || 1; // 1 ... correct > : > $str = 10 or 1; // 10 ... correct > : > $str = 0 or 1; // 0 > : > > : > > : > Either PHP doesn't support them well now, or its completely > : > broken! Any info? > : > > : > Perl reports: > : > > : > 10 ... correct > : > 1 ... correct > : > 10 ... correct > : > 0 ... correct, according to the precedence table, I reckon. > : > > : > Thank you! > : > > -- Zeev Suraski <zeev@zend.com> http://www.zend.com/