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Organization: Parliament Hill Computers Ltd
User-Agent: Mutt/1.5.20 (2009-12-10)
Subject: Re: [PHP-DEV] [RFC] Binary String Comparison
From: addw@phcomp.co.uk (Alain Williams)

On Mon, Aug 18, 2014 at 02:44:36PM +0200, Marc Bennewitz wrote:

> >What exactly is wrong with ===, strcmp(), etc..?
> 
> The question isn't "What's wrong with ===, strcmp()?" but "What's
> wrong with ==, <, >?".
> 
> We have a standard way to compare two operands but currently we do
> some magic things to solve something that don't need to be solved.
> 
> If you would like to compare two pears we currently convert the
> pears into apples and compare two apples and say please use a
> special function to compare two pears. Why?
> 
> There is no numeric context to compare two strings numerically.

I don't want to start a flame war, but perl gets it right, you have 2 sets of
operators 'eq' and '=='.

The choice to have a type juggling '==' was made years ago, that should not change.

If you want '<=' with strings, use strcmp().


There is also a speed cost to type juggling (PHP 5.3.3, 64 bit centos):

$a = "1234";
$b = "ghij"

$a == $b is about 64% slower than $a === $b
strcmp($, $b) is about 163% slower than $a === $b

$a = "abcd";
$b = "ghij"

$a == $b is about 24% slower than $a === $b
strcmp($, $b) is about 168% slower than $a === $b

$a = "abcd";
$b = "4567"

$a == $b is about 20% slower than $a === $b
strcmp($, $b) is about 176% slower than $a === $b

$a = "1234";
$b = "4567"

$a == $b is about 20% slower than $a === $b
strcmp($, $b) is about 162% slower than $a === $b

-- 
Alain Williams
Linux/GNU Consultant - Mail systems, Web sites, Networking, Programmer, IT Lecturer.
+44 (0) 787 668 0256  http://www.phcomp.co.uk/
Parliament Hill Computers Ltd. Registration Information: http://www.phcomp.co.uk/contact.php
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