'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

tag inside php...
hi


Code: <?php
echo "<td width="$columnWidth%" align=&

SAP Project Module
I have seen in the SAP Project Module,plan cost and budget are not equal and even difference is sign

cPanel API
Hi Guys,

Need a little guidance. I'm trying to get my script to communicate with cPanel (or W

creating a 1 to 100 in a table
hi guys I am a newb in php need some help.

I have a table with 1 column and 100 rows and in

Comparing MySql data and arrays.
I have a mysql table set up like this:
idsubjectbodyuseriddatetimetags1blog subjectblog body111|2

Php If in MySql query (hiding labels if a field is empty)
Okay, I've been trying to do this for a while, and I'm finally going to ask for help so I can get th

How can I uploading Transactional Data from Legacy to New SAP system
Hell Gurus,

I am overwhelmed with questions on how to migrate huge volume of Sales Orders

Protecting forms
Alright, I want to protect some forms of mine from SQL Injections, because I had someone earlier spa

Baffled by Undefined Index in Simple Array: Please Help!
Hello. I have a form which posts an array to this script. However, I can't seem to access the values

Using the $_GET variable to view certain records
Hello,

First let me explain my problem, I have 2 pages the first page pull a list of Guide ti

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