'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

How to insert random unique values in 2 columns ?
I have table with 2 columns

Create Table code_for_code (
first_code varchar2(10) uni

if description does not contain the following words
Hello everyone,

I am parsing a MS Excel (.xls) file and adding it's content to a mySQL databa

media recovery
Hi,
i startup the database i got the error

SQL> startup
ORACLE instance started.

ob_ dynamic content
i was wondering about the potential to use ob to create a <div then remove it when the page

My XSRF Prevention code isn't working
First of all, thanks for the generous help you guys have given me in the past on this forum.
Seco

Automatic Webpage ??
I have a page www.mysite.com/test.php with a
<form>
<textarea name=&q

Error in write byte array into document in SM58
Hi Gurus,

Getting the following error status in Transactional RFC (SM58) ..... *Error i

smart reading from a text file
Hello there fellow coders, i was wondering if one of you wouldnt mind helping me with this problem i

Setting a default timezone?
I have read about how to change the timezone in PHPMYADMIN, but it changes back, it doesn't STAY the

Compare user input to flat file data
Help...Am a complete newbie to programming so my code is prolly quite long. Am trying to verify a us

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