If you want to know the name of a variable, you usually try to do something stupid. Most times, the answer is to use a hash instead. Also in this case, you can use a hash to get named parameters instead of positional parameters.
Something like this:
sub blah
{
my %args=(@_);
foreach my $needed (qw( foo bar baz )) {
exists $args{$needed} or die "blah() needs a $needed parameter
+";
}
# ....
}
blah(foo => 42, bar => "don't forget this", baz => 'oh!');
blah(foo => 42, baz => 'oh!'); # <-- will die()
Back to the "what's the name of the variable problem". What should a hypothetical nameThatVariable() function return for the following cases?
$foo=42;
print nameThatVariable($foo); # '$foo', of course.
$foo=[ 42 ];
print nameThatVariable($foo); # still '$foo'.
@bar=( 42 );
print nameThatVariable(@bar); # '@bar', of course.
$baz=$foo=\@bar;
print nameThatVariable($foo); # 'reference to @bar' or '$foo'?
print nameThatVariable($baz); # 'reference to @bar' or '$foo' or '$baz
+' ?
print nameThatVariable(\@bar); # 'reference to @bar'?
print nameThatVariable(do { my $tmp=23 }); # '$tmp'?
print nameThatVariable([ 23,45 ]); # ?
Alexander
--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.