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"or" vs "||"

Posted on 1998-10-25
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Last Modified: 2010-03-04
What is the difference between "or" and "||" in general and in the following source particulary:

#!/usr/bin/perl -w
use strict;

my @allowed;

@allowed = fillnodes() or die "Error!\n";
print "@allowed\n";

@allowed = fillnodes() || die "Error!\n";
print "@allowed\n";

sub fillnodes {
    my @nodes;
    @nodes = (@nodes, 'first');  
    @nodes = (@nodes, 'second');  
    return @nodes;
}
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Question by:dda
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6 Comments
 
LVL 85

Expert Comment

by:ozo
ID: 1205700
#they differ in precedence

@allowed = fillnodes() or die "Error!\n";
#parses as
(@allowed = fillnodes()) or die "Error!\n";

@allowed = fillnodes() || die "Error!\n";
#parses as
@allowed = (fillnodes() || die "Error!\n");
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Author Comment

by:dda
ID: 1205701
Ok. Thanks.
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Author Comment

by:dda
ID: 1205702
2ozo: Why do you leave this question unlocked?
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LVL 85

Expert Comment

by:ozo
ID: 1205703
I wanted to be sure the question was fully answered before locking.
I take it the difference is clear now?
perldoc perlop
also explains this
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Author Comment

by:dda
ID: 1205704
Yes, thanks. You helped greatly.
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LVL 85

Accepted Solution

by:
ozo earned 200 total points
ID: 1205705
#they differ in precedence

@allowed = fillnodes() or die "Error!\n";
#parses as
(@allowed = fillnodes()) or die "Error!\n";

@allowed = fillnodes() || die "Error!\n";
#parses as
@allowed = (fillnodes() || die "Error!\n");
0

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