'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

Using unserialize()
Hi there.

I have some data in my database that is serialized.

e.g.

a:2:{i:0

preg-match with a string and numbers
Hi, I can't get the expression to work for my preg_match, what I'd like is for it to match the strin

TimeZoneOffset
Hello,

Please i need your help. I have a system that users can use to punch in and out. This

INSERT data problem!
After having an string with apostrophes ', double quotes " or any other special characters, suc

Execure stored procedure on a timer
Can someone tell me an easier way to execute a stored procedure on a timer? I am using Oracle 10g R

HTML Email rec'd as Source Code
The code does create and send the email successfully. However, the message shows as html code and n

opening a window with after form submission
I know this this forum has nothing to do with JS, but i'm trying to use it with my php script.
<

C++ Http request?
Code: string Response = "LOGIN_UNSUCCESSFUL"; System.Net.WebRequest request = Sy

$action = "insert"; //$action = $_GET['action'];
$action = "insert";
//$action = $_GET['action'];

why is this invalid type? I am

tell csv import script to ignore blank rows?
Hi i have the below script but i get an error if a row is blank ie a return in the csv file at the e

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