'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

Probably a simple error...
I'm getting the error -- Parse error: syntax error, unexpected '{' in /home/content/c/s/t/csteffen24

please help me in this update statment
hi every one

if I have table and this data in it

id name
10

Writing Windows Device Drivers with C
Yes: one of the nice features of C is void*. You can put anything there and get anything out. Very

need help to creat database
Hello Team, please guys i am stuck from three days with paypal issue for IPN but no luck yet now i w

How to replace search button with link?
hi to everbody.
i have a search submit form and button like this :

<form id="f

Results from Db outputted twice
Hey guys.. for come reason my data is outputted twise shown in the image below and i cant figure out

What am I missing here? Help!
Hello all!. I can't seem to get this working right. Well - it renders right, but something is goin

shift numbers with paging
Hi

How would i be able to display 10 numbers 1 2 3 4 5 6 7 8 9 10
and when I click next

Simpler method of getting variables from mysql
Hi Guys,

I'm trying to streamline my CMS's code and as I was writing a new page it occured to

How do I get the row number from from an sql table query
Hi all

I have a table that I query and it returns a number of rows.
mysql_num_rows($query)

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