'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

Display the user's weight lost in the past week
Hello everyone,

I am working on a weight loss app for my site, and I want to display the user

max() problem
I have a while loop to get image names.
Code: $imagequery = mysql_query("SELECT * FROM ad_i

switch not getting value
what am i doing wrong?
i want to populate the country list according to the category
i want to

ereg_replace()
Basically what i need to do is

$title = "This Suck's"

$striped = ereg_repl

Warning: mysql_num_rows() expects parameter 1
When i add quote at the end of this link
example:http://localhost/articlemania/category.php?cid=3

convert static html data into dynamic
hi all

i need to convert a website which has static above 2000 articles into dynamic and add

Display error above the login forum help!
Hi guys. just so you know im not asking for someone to do this for me I just need to be pointed in t

upload form file types....
Hey all, I am learning PHP and I am writing a script from the W3C Schools tutorials for uploading fi

Looking for help on using joining mysql tables and php....
Does anyone have any good links to references on how to pull mysql data, through joining tables and

CHECH A STRING FOR ' " ' (DOUBLE QUOTES)
I am checking for delimiter (.!?) and if there is a " after a sentence then it should neglect a

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