Comparing numerical strings

clintonium

Hi all. I'm asking this question simply out of curiosity -- I don't need the answer for what I'm working on because I've gone in a different direction.

From the PHP manual:
"If you compare two numerical strings, they are compared as integers."

and from the same page, two vars are considered identical "if $a is equal to $b, and they are of the same type."

Here's a link to the man page I'm referencing:
http://us2.php.net/manual/en/language.operators.comparison.php

So why is it that tests result in the following:

7 == 007 // true
'7' == '007' // true
7 === 007 // true
'7' === '007' // false

Doesn't it seem like the strings '7' and '007' should evaluate as identical, given the criteria described in the manual?

ClarkF1

They do in the second one, in the final one it's checking the type as well so it will evaluate them as strings rather than integers

You might want to check out http://us2.php.net/manual/en/types.comparisons.php which is the type comparison tables

clintonium

Thanks ClarkF1. So you're saying that using the identical operator stops PHP from implicitly converting the strings to integers during the comparison. That's what I couldn't find any discussion on in the manual.

Earlier today I was looking at the comparison tables that you cited and didn't see anything that seemed to address this question. Did I miss it? If there's a relevant example on that page could you point it out?