Comments on: Stupid PHP Tricks: (true == false)

By: Webspace Creations

Webspace Creations — Wed, 23 Dec 2009 17:09:20 +0000

When something as basic as comparisons do not function as expected, this is a serious problem and it is a problem that hackers are exploiting RIGHT NOW. Programmers aren’t lazy, they want a consistent programming environment. Many are coming from strict languages like C/C++. An expression like (‘1a’ == 1) should not evaluate as true. Loose typing would mean that (‘1′ == 1) evaluates as true, but PHP tries too hard to make an expression work and the === convention is an oddity (meaning any programmer with real experience is going to be unfamiliar with it). Weak typing is fine, but fundamental operations, such as comparisons, should work in a consistent and predictable way if we’re going to get serious about building secure web apps.

By: pbean

pbean — Thu, 19 Nov 2009 21:21:40 +0000

=== to the rescue… I have been using it more and more. But in my opinion the whole language is a mess and should get a big overhaul. Just have a look at these different kinds of constructs which can, in some situations, do the same or worse have completely unexpected behavior:

if (isset($a)) …
if (is_null($a)) …
if ($a == null) …
if ($a === null) …
if ($a) …
if (!!$a) …

By: Sava

Sava — Tue, 01 Sep 2009 07:45:23 +0000

Probably because 00 = 0 ? :D

By: Javi

Javi — Thu, 23 Apr 2009 09:02:47 +0000

I searched Google for php “true == false” and found your post.

The reason was, today I ran into the same example as you did. But in my case, I think it’s even funnier/more stupid.

Just assign $a = ‘00′ and $b = ‘0′. The same conditions apply to these values, and the universe is broken again.

Why in the world do two different strings evaluate to be the same? Who knows.

By: James Lawrie

James Lawrie — Fri, 19 Dec 2008 11:54:01 +0000

Nick – this doesn’t make PHP a weakly typed language any more than having the symptoms of influenza gives you the flu. PHP *is* weakly typed (it’s often referred to as duck-typed – if it quacks like a duck, it’s probably a duck) – this is just a symptom of that.
Maybe you are inferring that the word “weakly” infers this is a bad thing, whereas it doesn’t, it’s just the name for this kind of typing.

By: Link Flood - 09/11/2008 | 1337hax0r.com

Link Flood - 09/11/2008 | 1337hax0r.com — Mon, 08 Dec 2008 20:53:52 +0000

[...] (true == false)? Apparently it does in PHP. [...]

By: Nick | Resource Pile

Nick | Resource Pile — Mon, 29 Sep 2008 13:29:19 +0000

Nice, but I wouldn’t go as far to say this makes php a weakly typed language. It’s a good thing. Yes, you can do the above, but the aim of such a language is to create things, so the easier it is to create them (while remaining fast and relatively-low on code), the better the language in my eyes.

By: David Mackey

David Mackey — Tue, 09 Sep 2008 20:37:24 +0000

Nice article. :) Stumbled on ya.

By: Frank

Frank — Mon, 08 Sep 2008 11:04:48 +0000

… that is why we have strict comparisons with === and !==

By: Oliver Ong

Oliver Ong — Mon, 25 Aug 2008 14:10:10 +0000

CPP, um i would rather use php to do websites than use c/c++ or even asm. lets see who finishes creating a db add edit and delete transaction first.