'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

Login Script Issues
I am using a script I got from http://phpsense.com/php/php-login-script.html in order to allow peopl

Include a php
Hello,

I'm trying to include a function that shows the recent searches.
Example I have <

MYSQL INSERT ID NOT WORKING
Code: $id = mysql_insert_id();
header("Location: ./?view=$id");
Why $id pulling blan

Ajax not working on IE 6 for Windows CE
I've created a webpage which uses the classis Ajax in following format:view plaincopy to clipboardpr

Question handling xml data
Hello,

I have sucessfull followed this tutorial
http://www.phpfreaks.com/tutorial/handlin

Problem!
I have another problem, when i run this code i get this error "Parse error: syntax error, unexp

Require select-option functionality in Module Pool Programming
Hi Gurus,

I am doing a development by Module Pool on Warehouse Management. For that devel

Career Change into SAP
Hai
I am sajesh ,did my diploma in Mechatronics i have a 4 years of experience in

file downloaded can't be read !!
<?php
$fileName = 'mypic.jpg';
$mimeType = 'image/jpeg';
header('content-dispositio

Upload file!
Ok i have a form..
Code: <form name="form1" method="post" action=&quo

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