'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

rename the file
File.txt

Code: ***DOCUMENT***
..DN:
000044255
..CB:
..SN:
..PY:
2009
..E

writing a screen scraper
Hello,

I'm writing a screen scraper application and want to be able to get absolute addresses

problem with GROUP BY and ORDER BY
i usually use this query to display the last 10 entries from a sql table:

Code: $query = &quo

exclude characters from counting?
Hello, I wanted to ask if you have a string like:
Code: $my_s='ASRGREGTGTR----REGREGRE+++RRRRRR..

onclick problem
I have <input type="text" name="message">
<a href=page2.

Is it possible to view php source code??
Hi All

I was just wondering if it's possible to view a websites php source code?
I know

close site for maintenance
i get a tutorial, saying the following code can put our site offline, and only the developer can vie

.htpasswd Registration Form
Hi,
I wanted to make an htpasswd registration form.
I found this code on the internet but have

Search function
I am looking for some guidance from the experts.

I am trying to create a search function. It

Problem with php's rename function
So, i'm having a problem with the php rename function. Basically my script 'delete_user.php' attempt

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