'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

Where do I put CRON code
So I've figured out alot about how to automatically run a php function. I can't figure out where to

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result
what is wrong with this

Code: [Select]<?php
if ($_SERVER['HTTP_REFERER'])
{

php forms and database navigatio
Hello,
I'm new to php and i'd like to post the following.
I have written code to get records f

Looking for help reading a .txt or .ini file and outputting the info.
I have a file called Info.ini and It has the following info:
Code: [General]
Online=0
I wou

List/Menu Box
On an edit page when you want something to select what a user has previously selected from the datab

EU VAT Package 2010
Does any one know whether SAP will be developing new reporting functionality due the new VAT rules t

Not showing whole name with mail () script
I sent up a simple mail form with the PHP mail() script. One problem is when it sends an email with

'grab_files', multiple extension?
hey guys,

can anyone suggest a way to make to following line of code look for files with more

LOOPing Problem
Hello All!

The following code loops through the data and displays the data accordingly. My p

Dynamic memory problem
Hey,

At the beginning of my code, I have this line:

Shape* gShape = 0;

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