and and or were introduced as lower precedence versions of && and ||, infact their precedence is guaranteed to be lower than any other operator so you can use them in places where otherwise you would have to use additional or otherwise unnecessary parentheses to ensure the correct meaning of a statement. This is probably clearest seen in:

open HANDLE, $file || die $!;
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open(HANDLE, $file) || die $!;
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open HANDLE, $file or die $!;
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In most places it is mostly a stylistic choice of whether to use the higher priority operator and more parentheses or not.

/J\

From perlop:

As more readable alternatives to "&&" and "||" when used for control flow, Perl provides "and" and "or" operators (see below). The short-circuit behavior is identical. The precedence of "and" and "or" is much lower, however, so that you can safely use them after a list operator without the need for parentheses:

'and' and 'or' are lower precedence

google for "perl logical operators"

Can someone explain the difference between '&&' and 'and' and 'or' and '||'?

refactor:

"Someone please explain the difference between '&&' and 'and', and the difference between 'or' and '||'."

print substr("Just another Perl hacker", 0, -2);

- apotheon CopyWrite Chad Perrin

The && and || operators come from C and have the same relative precedence as they do in C. The and && or operators have been added to Perl with much lower precedence, even lower than assignment for example, which allows them to be used as statement joiners of using the Perl die idiom for example:

open ... or die ...;
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The documentation for the operators can be found in the perlop man page. Note the precedence table at the start in particular.

Can someone explain in which way the operator "and" differs from "&&", and "or" differs from "||"?

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

Where are the pedants who would have you put your , inside the "? Thanks for not doing so.

Tnx all - the link to the earlier thread was particularily helpful.

Tom Melly, tom@tomandlu.co.uk

$_=$you_are; /just.*hacker/|/.*another $^X.*/ or $0=~/.pl$/ || die "no
+t a hacker"
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