After seeing this question posted again and again and again, knocked off a quick solution. Suggestions welcome as I really haven't tested this completely (used parts of it elsewhere, but not all at once).

To use this call to_javscript() with two arguments: the javascript variable you want to create and the value you want to pass. The string returned will be correct javascript, ready to print.

Passing a scalar (or scalar ref) gets you a simple assignment (numeric or string). Passing an arrayref gives you a javascript array all filled in. Passing a hashref gives you a javascript Object, all filled in. Multi-level constructs need not apply. Passing undef gets you null.

ToDo: A simple modification (passing a reference to a namespace) could be used to pass an entire namespace to Javascript. That'd be cool. 

# From the FAQ
sub getnum {
        use POSIX qw(strtod);
        my $str = shift;
        $str =~ s/^\s+//;
        $str =~ s/\s+$//;
        $! = 0;
        my($num, $unparsed) = strtod($str);
        if (($str eq '') || ($unparsed != 0) || $!) {
                return undef;
        } else {
                return $num;
        }
}

sub assignsafe {
        my($string)=shift;
        return "null" if ! defined $string;
        $string=~s/([\x5C\x22\x00-\x1f\x7f-\xff])/sprintf('\x%02x', or
+d($1))/ge;
        if (defined getnum($string)) {
                return $string;
        } else {
                return qq{'$string'};
        }
}
sub to_javascript {
        my($name, $value)=(shift, shift);
        my $r="";

        warn "to_javascript argument mismatch: (name, value)" if @_;
        # Determine what $value is exactly
        if (ref $value and ref $value ne "SCALAR") {
                if (ref $value eq "HASH") {
                        $r="var $name=new Object();\n";
                        foreach(keys %$value) {
                                $r.="$name.$_=" . assignsafe($value->{
+$_}) . ";\n";
                        }
                }  else {
                        $r="var $name=new Array();\n";
                        for($_=0; $_<=$#{$value}; $_++) {
                                next unless exists $value->[$_];
                                $r.="$name\[$_]=" . assignsafe($value-
+>[$_]) . ";\n";
                        }
                }
        } else {
                if (ref $value) {
                        @_=($name, $$value);
                        goto &to_javascript;
                }
                print qq{var $name=} . assignsafe($value) . qq{;\n}; #
+ 
        }
        return $r;
}

# Some tests....
print to_javascript('sref', \5);
print to_javascript('scalar', 5);
print to_javascript('null', '');
$a="halgha";
print to_javascript('string', $a);
print to_javascript('stringref', \$a);
print to_javascript('stringnl', "foo\nbar");
print to_javascript('stringtilde', "foo\xB0bar");
print to_javascript('hashref', { foo => 'bar', baz => 'poit' });
@arr=(1,2,3);
print to_javascript('array', \@arr);
$arr[5]="hlagh";
print to_javascript('arraysparse', \@arr);
print to_javascript('undef', undef);

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In reply to "Passing variables to Javascript" by clintp

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