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From: ShaunJ on 15 Apr 2008 13:24
I want to print a separator between each iteration of a foreach loop,
but not after the last element. How do I avoid printing the last
extraneous comma in the following code snippet?

foreach (@ARGV) {
print $_, ',';
}
print "\n";

In this simple example join ',' would suffice, but the real body of
the foreach loop is more complicated. What I want to do is something
like this:

foreach (@ARGV) {
print $_;
print ',' unless last_element;
}
print "\n";

Thanks,
Shaun
From: Frank Seitz on 15 Apr 2008 13:36
ShaunJ wrote:

> foreach (@ARGV) {
> print $_;
> print ',' unless last_element;
^^^^^^^^^^^^
\$_ eq \$ARGV[-1]
> }
> print "\n";

Frank
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From: J�rgen Exner on 15 Apr 2008 13:40
ShaunJ <sjackman(a)gmail.com> wrote:
>I want to print a separator between each iteration of a foreach loop,
>but not after the last element.

That's a standard problem in CS. You need to process the first or last
element outside the loop.

> How do I avoid printing the last
>extraneous comma in the following code snippet?
>[...] What I want to do is something like this:
>
>foreach (@ARGV) {
> print $_;
> print ',' unless last_element;
>}
>print "\n";

print $ARGV[0]; shift @ARGV
for (@ARGV) {
print ',';
print $_;
}

OR

for (@ARGV[0..(a)ARGV-2]) {
print $_;
print ',';
}
print $ARGV[$#ARGV];

jue
From: xhoster on 15 Apr 2008 13:44
ShaunJ <sjackman(a)gmail.com> wrote:
> I want to print a separator between each iteration of a foreach loop,
> but not after the last element. How do I avoid printing the last
> extraneous comma in the following code snippet?
>
> foreach (@ARGV) {
> print $_, ',';
> }
> print "\n";
>
> In this simple example join ',' would suffice, but the real body of
> the foreach loop is more complicated.

Unless it is huge, you could just change the print to be push @results, $_;
and then do the join on @results.


> What I want to do is something
> like this:
>
> foreach (@ARGV) {
> print $_;
> print ',' unless last_element;
> }
> print "\n";

I don't think there is a clean way to do it with a foreach loop. You
could use a counter, but if you are going to do that I'd just as soon
change to a C style loop:

for (my $i=0; $i<=$#ARGV; $i++) {
print $ARGV[$i];
print "," unless $i==$#ARGV;
};

But actually, I might go for:

for (my $i=0; $i<@ARGV; $i++) {
print "," unless $i==0;
print $ARGV[$i];
};

Xho

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From: Willem on 15 Apr 2008 13:47
ShaunJ wrote:
) I want to print a separator between each iteration of a foreach loop,
) but not after the last element. How do I avoid printing the last
) extraneous comma in the following code snippet?
)
) foreach (@ARGV) {
) print $_, ',';
) }
) print "\n";
)
) In this simple example join ',' would suffice, but the real body of
) the foreach loop is more complicated. What I want to do is something
) like this:
)
) foreach (@ARGV) {
) print $_;
) print ',' unless last_element;
) }
) print "\n";

One sometimes-seen useful trick is this:

my $sep = '';
foreach (@ARGV) {
print $sep; $sep = ',';
print $_;
}


SaSW, Willem
--
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made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT
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