'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

PL/SQL: ORA-00947: not enough values error message
Hi all i am getting Error(25,63): PL/SQL: ORA-00947: not enough values error message when executing

Xacute search within SQL results
I have a query that is pulling data, and I want to return a specific value from the results of that

TimeStamp Column Problem...
I'm mad at my self and thinking I'm a little retarded. It just be some one mistake I'm missing here.

phpMailer not working ..........
HI,
I was playing with the phpMailer script and tried to send a smiple mail using their test scri

upload image name with extension using php
hi frds..

<input id="file1" type="file" name="file[]" &a

php problem?
I don't think I'm stupid, but maybe I am.

I am working on a sit for a friend I am try to put

Schedule editor
Hi,

I have a question related to Schedule editor.
If we schedule a BLS for every 30

Mail Form receiving emails with no content
Hi, I hope someone here can help me.
I have a simple form in my website, it was working OK, after

insert quotes
Hi,

I have an output like this:
Code: john,18,Cancer
How can I change this to
Code:

login from external site
Hi my new experience begins, Now what i am trying to do is i make three pages, login.php logout.php

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