For the simple answer, it looks like you're trying to pass an array, @3, to your function. @3 is naturally empty, so @_ picks up the values in the array.

The first value in the array is 9, which $a gets set to in your function. You then change $LOCAL_CODEPAGE to $a at the end. (update: And you return that value, which is still, predictably, 9.)

Though I'm not one to criticize coding usually, I will note that you print "\n" at the end of your function, though you return before that. If for any reason the "return" part of your assignment of $LOCAL_CODEPAGE got taken out, you'd be returning the return value of the print, which I don't think is what you want.

I take it this function is a work in progress. I would rewrite it entirely, but I'm lazy. I'll just show you what I did looking at it: 
sub f1{
    
    my ($a) =@_;
    $cp=1;
        $LOCAL_CODEPAGE =10;
        print "This is $a\n";
        print $LOCAL_CODEPAGE;
    if ($a==1){
        $LOCAL_CODEPAGE = $cp;
        break;
    }
    return $LOCAL_CODEPAGE = $a;
    print "\n";
}
@3=(3,10, 13);  ## comment this out and see your value come back as 9
print "\$LOCAL_CODEPAGE=$LOCAL_CODEPAGE: f1(@3,9,3,4,5): ".f1(@3,9,3,4
+,5)."\n";

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In reply to Re: why this function call print 9 by SamCG
in thread why this function call print 9 by edwardt_tril

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