Control Structures

"&&" and "||" as Control Structures

• In keeping with the perl philosophy that no command can be too short (this was inherited from Unix), it is possible to use "&&" and "||" as control structures.
• if ($x < 10) { print "$x < 10\n"; } could also be written as ($x < 10) && (print "$x < 10\n");
• Likewise, unless ($x < 10) { print "$x > 10\n"; } could also be written as ($x < 10) || (print "$x > 10\n");
• This works because Perl uses short circuit evaluation... in other words, the second part of the expression is only executed if the first part of the expression meets minimum.
• In other words, if Perl can see that the expression is going to be false by looking at the first part of the expression only, it does not even bother to look at the second part of the expression, and it is not executed.