'210010106140040100' == '210010106140040101'


Posted on 16th Feb 2014 07:03 pm by admin

Debugging this simple line of a PHP script

Code: if($a == $b){ }
I've found that with value of
Did you know?Explore Trending and Topic pages for more stories like this.
$a = '210010106140040100' (type = string)
$b = '210010106140040101' (type = string)

the result of the comparison is TRUE

the same if i compare 2 integer

$a = 210010106140040100 (type = int)
$b = 210010106140040101 (type = int)

$a == $b ( true )

If I use the === operator

'210010106140040100' === '210010106140040101' (comparison of strings: result is FALSE)
210010106140040100 === 210010106140040101 (comparison of numbers: result is TRUE)

I think it could be caused by the fact that the string is 'like' integer, but exceed the standard size of integer number.
But the final result remain a mistery for me: I've tested some others 'big' numbers and I've found for example:

18014398509481980==18014398509481981 (true) !!!!
18014398509481982==18014398509481981 (false) !!!!

In my specific script i can handle this specific comparison using the === operator, because i can assume that the variable are string.

But i'd like to know why this happen, and i'd appreciate suggestions about how to efficiently compare 'big' integers.

Thanks!

I use PHP 5.2 with IIS
No comments posted yet

Your Answer:

Login to answer
199 Like 53 Dislike
Previous forums Next forums
Other forums

Restricted access to sub-folder in iis6 doesn't work?
Basically I'm trying to add restriction to sub-folder (which contains pdf) in web.config for iis6 as

Get relative path from absolute path
How would one go about getting the relative path to a file from its absolute path?

Why do I get this error
Parse error: syntax error, unexpected T_STRING, expecting ',' or ';' in /home/a5488351/public_html/b

php file erros / need help please
Hello

Someone decoded a zend file for me.. after uploaded it on ftp i get some errors, i trye

Require select-option functionality in Module Pool Programming
Hi Gurus,

I am doing a development by Module Pool on Warehouse Management. For that devel

Staff Induction System - No idea where to go from here!!!
Hi there, I'm pretty new to PHP and Mysql so could really do with being pointed in the right directi

please help
HTML Code:

Code: <span id="ctl00"><span>

Having a problem get the selected item from a drop down menu
I have been looking at this for days now.

I have a drop down menu that get it's values from a

PHP/PKI
I am trying to set up a web application that uses pki. does anyone have a good tutorial to set this

Reading Most Recent CSV File in Directory
I thought I had wrapped this project up, but found out that the program I use to FTP a csv file to m

Sign up to write
Sign up now if you have flare of writing..
Login   |   Register
Follow Us
Indyaspeak @ Facebook Indyaspeak @ Twitter Indyaspeak @ Pinterest RSS



Play Free Quiz and Win Cash