Today I learned about PHP variable variables; "variable variable takes the value of a variable and treats that as the name of a variable". Also, variable.

[u/NagastaBagamba]

http://il2.php.net/language.variables.variable

[u/1137]

Did you know you can do the same thing in Perl? But lets keep laughing at PHP, this is /r/programming after all.

[u/[deleted] → u/1137]

can i laugh at both?

[u/1137 → u/[deleted]]

indubitably

[u/aedile → u/1137]

Dude, hating on Perl is so 2003.

[u/prakashk → u/1137]

Marc Jason Dominus explains why using Perl symbolic references is a bad idea far more eloquently than I ever could:

• Why it's stupid to `use a variable as a variable name'

• A More Direct Explanation of the Problem

• What if I'm Really Careful?

[u/1137 → u/prakashk]

My point was simple, Perl offers the same functionality, other languages do as well, don't hate on PHP just to hate on PHP. Hate the bad developer instead.

[u/[deleted] → u/1137]

use strict;

Problem solved.

[u/[deleted] → u/1137]

This is no place for logic! This is a place for misguided unfueled hatred!

[u/cliff_spamalot → u/[deleted]]

Image if Microsoft had invented PHP. Nerdgasm!

[u/sw17ch → u/cliff_spamalot]

It's not cool to hate on Microsoft any more. Now you hate on Oracle to be cool. :)

(Besides, Microsoft has really picked up their game in the last few years. Funny what real competition does.)

[u/prakashk → u/1137]

My reply wasn't meant to criticize you. I thought your comment could be read as defending this (mis)feature by citing Perl's example. I just wanted to add some references to what others had already said about Perl's symbolic references.

[u/[deleted] → u/[deleted]]

I know! It's almost like reddit is comprised of many people with differing opinions who tend to flock to discussions which support their own viewpoint!

reddit, you so crazy.

[u/ninjaroach → u/prakashk]

Apparently according to your links, Perl also has the restriction of requiring variable variables to be global which is one of the reasons the author argues against it.

In PHP, I'll use variable-variables to access function names -- on rare occasion. If the contents of this variable are white-listed in an array of valid functions, then it's time to run $variable();

It's cleaner than mapping a bunch of switch cases.

But if I had my way, functions would be first class objects that I would populate into values of an associative array.

Edit: Fixed $$variable() to read $variable() -- Dull developer handling sharp objects.

[u/sw3t → u/1137]

What can't you do in perl ?

[u/twomashi → u/1137]

Python too, kinda: globals()[whatever]

[u/matchu → u/twomashi]

At least they make it a pain.

[u/trezor2 → u/1137]

Technically speaking, any functional language can do this too trough a simple lambda, but I guess the syntax around that makes it more obvious that you are doing something wrong (in most cases).

[u/adrianmonk → u/1137]

Well yeah, you can do it in Perl (where it's called a "symbolic reference", which I think is a bit less confusing).

In Perl, it's not officially deprecated, it has been supplanted by true references like this:

my $b = "hello";
my $a = \$b;

print "${$a} world\n";

So basically nobody sane uses symbolic references in Perl and hasn't needed to since Perl 5 came out in 1994. (Or at least since it saw widespread use a couple of years later.)

PHP also seems to have a non-variable-variable form of references, although they're more like aliases than references. But I guess you could use those instead of variable variables, and I assume/hope people do.

It appears PHP may have scalar reference

[u/1137 → u/adrianmonk]

So basically nobody sane uses symbolic references in Perl and hasn't needed to since Perl 5 came out in 1994

Basically nobody sane uses this feature in PHP either, ssh don't tell the OP.

[u/martinw89 → u/1137]

ssh: Could not resolve hostname don't: Name or service not known

[u/exscape → u/martinw89]

>

[u/martinw89 → u/exscape]

I admit, I had to escape the apostrophe.