PHP 5.4.31 Released

version_compare

(PHP 4 >= 4.1.0, PHP 5)

version_compareCompares two "PHP-standardized" version number strings

Description

mixed version_compare ( string $version1 , string $version2 [, string $operator ] )

version_compare() compares two "PHP-standardized" version number strings.

The function first replaces _, - and + with a dot . in the version strings and also inserts dots . before and after any non number so that for example '4.3.2RC1' becomes '4.3.2.RC.1'. Then it compares the parts starting from left to right. If a part contains special version strings these are handled in the following order: any string not found in this list < dev < alpha = a < beta = b < RC = rc < # < pl = p. This way not only versions with different levels like '4.1' and '4.1.2' can be compared but also any PHP specific version containing development state.

Parameters

version1

First version number.

version2

Second version number.

operator

If the third optional operator argument is specified, test for a particular relationship. The possible operators are: <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne respectively.

This parameter is case-sensitive, values should be lowercase.

Return Values

By default, version_compare() returns -1 if the first version is lower than the second, 0 if they are equal, and 1 if the second is lower.

When using the optional operator argument, the function will return TRUE if the relationship is the one specified by the operator, FALSE otherwise.

Examples

The examples below use the PHP_VERSION constant, because it contains the value of the PHP version that is executing the code.

Example #1 version_compare() examples

<?php
if (version_compare(PHP_VERSION'6.0.0') >= 0) {
    echo 
'I am at least PHP version 6.0.0, my version: ' PHP_VERSION "\n";
}

if (
version_compare(PHP_VERSION'5.3.0') >= 0) {
    echo 
'I am at least PHP version 5.3.0, my version: ' PHP_VERSION "\n";
}

if (
version_compare(PHP_VERSION'5.0.0''>=')) {
    echo 
'I am using PHP 5, my version: ' PHP_VERSION "\n";
}

if (
version_compare(PHP_VERSION'5.0.0''<')) {
    echo 
'I am using PHP 4, my version: ' PHP_VERSION "\n";
}
?>

Notes

Note:

The PHP_VERSION constant holds current PHP version.

Note:

Note that pre-release versions, such as 5.3.0-dev, are considered lower than their final release counterparts (like 5.3.0).

Note:

Special version strings such as alpha and beta are case sensitive. Version strings from arbitrary sources that do not adhere to the PHP standard may need to be lowercased via strtolower() before calling version_compare().

See Also

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User Contributed Notes 10 notes

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9
eric at themepark dot com
10 years ago
[editors note]
snipbit fixed after comment from Matt Mullenweg

--jm
[/editors note]

so in a nutshell... I believe it works best like this:

<?php
if (version_compare(phpversion(), "4.3.0", ">=")) {
 
// you're on 4.3.0 or later
} else {
 
// you're not
}
?>
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3
opendb at iamvegan dot net
7 years ago
Something that may trip some folks up, but is useful to mention is that the following version comparison does not work quite as I expected:
    version_compare('1.0.1', '1.0pl1', '>')

However, its quite easy to get working:
    version_compare('1.0.1', '1.0.0pl1', '>')
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2
arnoud at procurios dot nl
9 years ago
If you're careful, this function actualy works quite nicely for comparing version numbers from programs other than PHP itself. I've used it to compare MySQL version numbers. The only issue is that version_compare doesn't recognize the 'gamma' addition that mysql uses as being later than 'alpha' or 'beta', because the latter two are treated specially. If you keep this in mind though, you should have no problems.
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2
loaded67 at hotmail dot com
4 years ago
This function is also usefull when working with multiple installations.

As php5.3+ will not have E_STRICT in the error_reporting anymore you can state:

<?php
ini_set
('error_reporting', (version_compare(PHP_VERSION, '5.3.0', '<') ? E_ALL|E_STRICT : E_ALL));
?>

Giving you all the error error reporting you want...
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1
rogier
2 years ago
Please note that supplying an operator that is not listed (e.g. ===), this function returns NULL instead of false.

Tested on PHP5.3.0, Win32
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1
sam at wyvern dot non-spammers-remove dot com dot au
10 years ago
Actually, it works to any degree:

<?php
version_compare
('1.2.3.4RC7.7', '1.2.3.4RC7.8')
version_compare('8.2.50.4', '8.2.52.6')
?>

will both give -1 (ie the left is lower than the right).
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0
insid0r at yahoo dot com
5 years ago
Since this function considers 1 < 1.0 < 1.0.0, others might find this function useful (which considers 1 == 1.0):

<?php
//Compare two sets of versions, where major/minor/etc. releases are separated by dots.
//Returns 0 if both are equal, 1 if A > B, and -1 if B < A.
function version_compare2($a, $b)
{
   
$a = explode(".", rtrim($a, ".0")); //Split version into pieces and remove trailing .0
   
$b = explode(".", rtrim($b, ".0")); //Split version into pieces and remove trailing .0
   
foreach ($a as $depth => $aVal)
    {
//Iterate over each piece of A
       
if (isset($b[$depth]))
        {
//If B matches A to this depth, compare the values
           
if ($aVal > $b[$depth]) return 1; //Return A > B
           
else if ($aVal < $b[$depth]) return -1; //Return B > A
            //An equal result is inconclusive at this point
       
}
        else
        {
//If B does not match A to this depth, then A comes after B in sort order
           
return 1; //so return A > B
       
}
    }
   
//At this point, we know that to the depth that A and B extend to, they are equivalent.
    //Either the loop ended because A is shorter than B, or both are equal.
   
return (count($a) < count($b)) ? -1 : 0;
}
?>
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0
Jonathon dot Reinhart at gmail dot com
6 years ago
I know this is somewhat incomplete, but it did a fair enough job for what I needed.  I was writing some code that needed done immediately on a server that was to be upgraded some time in the future.  Here is a quick replacement for version_compare (without the use of the operator argument). Feel free to add to this / complete it.

<?php
function version_compare2($version1, $version2)
{
   
$v1 = explode('.',$version1);
   
$v2 = explode('.',$version2);
   
    if (
$v1[0] > $v2[0])
       
$ret = 1;
    else if (
$v1[0] < $v2[0])
       
$ret = -1;
   
    else   
// Major ver are =
   
{
        if (
$v1[1] > $v2[1])
           
$ret = 1;
        else if (
$v1[1] < $v2[1])
           
$ret = -1;
       
        else 
// Minor ver are =
       
{
            if (
$v1[2] > $v2[2])
               
$ret = 1;
            else if (
$v1[2] < $v2[2])
               
$ret = -1;
            else
               
$ret = 0;
        }
    }
   
    return
$ret;
}
?>
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0
mina86 at tlen dot pl
10 years ago
Here's a wrapper which is more tolerant as far as order of arguments is considered:

<?php
function ver_cmp($arg1, $arg2 = null, $arg3 = null) {
  static
$phpversion = null;
  if (
$phpversion===null) $phpversion = phpversion();

  switch (
func_num_args()) {
  case
1: return version_compare($phpversion, $arg1);
  case
2:
    if (
preg_match('/^[lg][te]|[<>]=?|[!=]?=|eq|ne|<>$/i', $arg1))
      return
version_compare($phpversion, $arg2, $arg1);
    elseif (
preg_match('/^[lg][te]|[<>]=?|[!=]?=|eq|ne|<>$/i', $arg2))
      return
version_compare($phpversion, $arg1, $arg2);
    return
version_compare($arg1, $arg2);
  default:
   
$ver1 = $arg1;
    if (
preg_match('/^[lg][te]|[<>]=?|[!=]?=|eq|ne|<>$/i', $arg2))
      return
version_compare($arg1, $arg3, $arg2);
    return
version_compare($arg1, $arg2, $arg3);
  }
}
?>

It also uses phpversion() as a default version if only one string is present. It can make your code look nicer 'cuz you can now write:
<?php if (ver_cmp($version1, '>=', $version2)) something; ?>
and to check a version string against the PHP's version you might use:
<?php if (ver_cmp('>=', $version)) something; ?>
instead of using phpversion().
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-1
mindplay.dk
2 years ago
This little script can perhaps help you understand version comparison a little better - the output is displayed in the comment at the top. Tweak the list of versions if you need more examples...

<?php

#      1 lt 1.0
#    1.0 lt 1.01
#   1.01 eq 1.1
#    1.1 lt 1.10
#   1.10 gt 1.10b
#  1.10b lt 1.10.0

header('Content-type: text/plain');

$versions = array(
 
'1',
 
'1.0',
 
'1.01',
 
'1.1',
 
'1.10',
 
'1.10b',
 
'1.10.0',
);

$comps = array(
-
1 => 'lt',
 
0 => 'eq',
 
1 => 'gt'
);

foreach (
$versions as $version) {
  if (isset(
$last)) {
   
$comp = version_compare($last, $version);
    echo
str_pad($last,8,' ',STR_PAD_LEFT) . " {$comps[$comp]} {$version}\n";
  }
 
$last = $version;
}

?>
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