I have a number string with the following number :
$str=14.5;
I want to half up this value so that I get
15
I have tried this code
echo round($str,0,PHP_ROUND_HALF_UP);
But It doesn't work and I am getting errors :
Use of undefined constants "PHP_ROUND_HALF_UP" , "Wrong parameter count for round"
In PHP 5.3.0 the mode parameter was introduced. The errors suggest you are using an older version and are replicated here in older versions.
However, in older versions PHP_ROUND_HALF_UP is the default, so you shouldn't have an issue. Just use round($str, 0).
If you need to use different modes and must use version <5.3.0 there are other questions on the matter:
round() mode ROUND_HALF_DOWN with PHP 5.2.17
Related
I reinstalled WAMP and now I have PHP version 7.1.9 (before this I had 7.0 x).
A part of the code doesn't work anymore without warning/notice reports.
- Warning: A non-numeric value encountered in
And:
- Notice: A non well formed numeric value encountered in
The script with the error contains the following code:
$_POST['username'] = 'yourname';
$code = md5($_POST['username'] + microtime() ) ;
var_dump($code);
I believe that my problem arises as a result of upgrading my PHP interpreter.
I had better results with setting microtime to microtime(true).
The errors are even not there when I set $_POST['username'] to a number.
But like I said: I want to know what causes it and how to solve it.
I also read through the PHP migrating docs to find anything about microtime or variables regarding MD5 maybe, but nothing.
Could it be the settings are different in WAMP or could it be a bug in the PHP intepreter?
You get this error because starting with PHP7 the interpreter is a little less lax when doing type conversions.
Going by parts, you are trying to add (as in: using the addition operator, ++) two values and whatever you have in $_POST['username'] is certainly not a valid number; and the return of microtime(), by default, is not a valid number either.
Before PHP 7.1, this would work silently, and the intepreter would perform a silent type cast behind the scenes, never complaining. But on PHP >= 7.1, you need to be a bit more careful with types.
The suggested workaround of using the concatenation operator (.) works because of the result of microtime() and the contents of $_POST['username'] are both strings, and md5() expects a string as a parameter anyway.
$code = md5( $_POST['username'] . microtime() ) ;
I've found out unclear php behavior
echo '0x12' + 2; // 20
As I understand from http://php.net/manual/en/language.types.string.php string '0x12' should cast to 0 like '0b11' do
echo '0b11' + 1; // 1
Please explain why is it so.
UPDATE
First example give me 2 in 7.x and 20 in 5.x versions.
Thanks AntoineB and Mark Baker for the comments. From this point I can conclude it was more like an issue in php 5.x rather then feature and fixed in php 7.x (Backward incompatible changes for PHP7).
So, I have a PHP script:
<?
rand(1000000000000,9999999999999);
The expected result is a number with 13 digits.
But it's returning some weird numbers, as:
987419207
1032717476
-455563764
Does anyone know what's going on?
PHP: 5.2.17
OS: Tested on Debian Squeeze and Windows 7, both 64 bits
Solution (workaround)
<?
echo rand(10000,99999).rand(10000000,99999999);
Use getrandmax() to see the max value that you can get from rand(), its clearly a overflow problem.
you could use 2 of this int and make a longer one, calling rand for a 6 digit and again for a 7 digits, just an idea.
i think 10000000000000 its not a valid integer!
output
getrandmax();
Use a bignum library like BCMath or GMP. GMP is newer and seems to have a better API but that's just my opinion
I am including the same "random.inc" in foo.php and bar.php. For each, I want reproducible "random" results.
So in foo.php I always want one set of numbers and/or keywords. In bar.php another. Which shouldn't change on reload. That's what I mean by contant pseudo-random. And that's why I seeding on the url. However I still get different results for individual numbers as well as for array pickson every reload. This is the full php file:
<?
header('Content-Type: text/plain');
$seed = crc32( $_SERVER['REQUEST_URI'] );
echo "phpversion: ".phpversion()."\nseed: $seed\n";
srand( $seed ); // (seed verified to be contant as expected)
// neither single values nor array pics turn out deterministic
echo ''.rand(0,100).' '.rand(0,100).' '.rand(0,100)."\n";
$values = array( '0'=>21,'1'=>89,'2'=>96,'3'=>47,'4'=>88 );
print_r( array_rand( $values, 3 ) );
?>
In the days of PHP4.1 it was (verified) possible to achieve constant pseudo-random like this. array_rand API documentation describes as a feature that since 4.2 initialization happens automatically. Perhaps this is overriding any explicit seeding? (if so, perhaps explicit seeding should raise an internal PHP flag, preventing automatic seeding?). Btw: mt_srand() and srand() are equally not working.
I would really like to get my deterministic / constant pseudo-random back...
Update: Solution below (Windows and/or version 5.2 's fault)
Works for me (PHP/5.3.6):
<?php
$data = range(1, 100);
srand(1);
print_r(array_rand($data, 3));
... always prints:
Array
(
[0] => 21
[1] => 89
[2] => 95
)
... in my machine. Apparently, the exact numbers differ depending on the exact environment but they're reproducible.
Guys, you are all correct! (Sorry, I answer it myself now)
my web hoster runs 5.2.17 under Linux 2.6.36, and above problem exists.
under Win x64 5.3.0 everything works as expected.
So it's everyone's guess if that's an OS related bug and/or a PHP bug, fixed in 5.3.0.
Given that random constant seeding worked before, I am guessing they fixed in 5.3 the bug that came with the autoseed feature enhancement in 4.2. Anyway, Thanx again, at least there's clarity now.
The seeding functions are still available, and should still work; it's just since PHP 4.2 they are automatically seeded with the time on page load; but you can still call them to reset the random sequence to a known starting point.
[edit] I have just done a quick test program to make sure I wasn't imagining it!
mt_srand(50000);
print "rand="+mt_rand(0,10000);
Using PHP 5.2, this always results in the same value being printed (1749).
[EDIT]
As noted by #cwd and in the accepted answer to this question, there appears to be a discrepancy in PHP 5.2's behaviour with random number seeding between the Linux and Windows versions. In PHP 5.2 on Linux, the above technique does not appear to work.
Fortunately, the bug seems to have been fixed in PHP 5.3, so the solution to this problem is simply to upgrade. (PHP 5.2 is not supported any longer, so you should upgrade anyway)
Btw, if anyone else wants "constant windows-pre-5.3 pseudo-random" (of low quality, e.g. for stuff like SEO buzzwording) this is a tested workaround:
$r = abs(crc32($URL))%20; // a number between 0 and 19, based on URL
In PHP 5.2.17 and probably on all versions of PHP 5.2, (not sure about windows), we lose the capability of generating random numbers based on a seed as PHP changes the algorithm used for random numbers.
rand and mt_rand are "broken" not only because they will not give one random number, but they will also not give a same sequence of random numbers - even when using a seed!
At first the PHP developers tried to argue that this is the way that it "should" work, but we can guess they caught enough grief about the problem that they have reverted the way that it works with PHP 5.3.
See the php mt_rand page and the bug tracker to learn about this issue.
Okay, so I'm getting my MySQL Version like so:
preg_replace('#[^0-9\.]#', '', mysql_get_server_info());
Which gives me a number like: 5.1.36
That's all good. What I need to do, is compare that version with another version. I was about to attempt to write my function to compare them, when I thought of version_compare(). However, upon testing I became unsure, but perhaps I'm just not sure how MySQL Version Numbers work.
This is what I tested:
version_compare('5.1.36', '5.1.4', '<');
or
5.1.36 < 5.1.4
I assumed that this would return true, that 5.1.36 is less than 5.1.4. My reason for that is, I figure 5.1.4 is actually 5.1.40 not 5.1.04. Perhaps I'm wrong there.
So am I thinking wrong, or is the function returning the incorrect result?
The function is correct. The numbering system is M.m.r where each "number" is a decimal number.
M is the major version number
m is the minor version number
r is the revision number
So 5.1.36 would be revision 36 of the 5.1 minor version... Therefore, 5.1.4 would be revision 4 (and hence 36 > 4)...
http://php.net/version_compare :)
http://www.php.net/manual/en/mysqli.get-server-version.php
mysqli's get_server_version() method will return the version as an integer.
main_version * 10000 + minor_version
* 100 + sub_version (i.e. version 4.1.0 is 40100).
I assumed that this would return true,
that 5.1.36 is less than 5.1.4. My
reason for that is, I figure 5.1.4 is
actually 5.1.40 not 5.1.04. Perhaps
I'm wrong there.
Yes, 5.1.36 is greater than 5.1.4.