'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

Progress bar tracking file downloads
Hey guys, was wondering if there was a way to track how far a file has been downloaded. I know there

Need help with an email blocker for a guessbook
I am new with php and here is a simple guessbook page but I am being hit with spam from a group of t

Need help with some php code :)
Hey! I'm quite new to this whole thing, so please don't fire me with shait on this one =D

I'm

Uploading Filetypes and placing them in seperate folders.
Hello,

first post , and asking for help im afraid. Very new to PHP, was making good progress

dynamic table with forms
I have a table that is populated with mysql data and in teh first column there is a raido button tha

mysql query with single quotes in a variable
$sitedetails = "INSERT INTO vars (address, sitename, description, ownername, theme) VALUES ('$u

Legal Issues for SAP ERP o ERP in general
Hi experts,

Can someone please help me finding some documentation about legal issues tha

How to update this array?
I am saving a string that looks this: username1, username2, username3...
into a single cell in a

Business Health Check
Hello

I need to create an online business health check for a client it will be multiple choi

mysql_affected_rows() usage
Possibly a MySQL issue, but the function that is not behaving in the anticipated way is a PHP functi

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