[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
}
?>
version_compare
(PHP 4 >= 4.1.0, PHP 5, PHP 7)
version_compare — Compares two "PHP-standardized" version number strings
Opis
version_compare
( string
$version1
, string $version2
) : int
version_compare
( string
$version1
, string $version2
, string $operator
) : boolversion_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.
Parametry
-
version1 -
First version number.
-
version2 -
Second version number.
-
operator -
If the third optional
operatorargument 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.
Zwracane wartości
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.
If an unsupported operator is given, NULL is returned.
Przykłady
The examples below use the PHP_VERSION constant,
because it contains the value of the PHP version that is executing
the code.
Przykład #1 version_compare() examples
<?php
if (version_compare(PHP_VERSION, '7.0.0') >= 0) {
echo 'I am at least PHP version 7.0.0, 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 at least PHP version 5.0.0, my version: ' . PHP_VERSION . "\n";
}
if (version_compare(PHP_VERSION, '5.0.0', '<')) {
echo 'I am still PHP 4, my version: ' . PHP_VERSION . "\n";
}
?>
Notatki
Informacja:
The
PHP_VERSIONconstant holds current PHP version.
Informacja:
Note that pre-release versions, such as 5.3.0-dev, are considered lower than their final release counterparts (like 5.3.0).
Informacja:
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().
Zobacz też:
- phpversion() - Gets the current PHP version
- php_uname() - Returns information about the operating system PHP is running on
- function_exists() - Zwraca TRUE jeżeli dana funkcja została zdefiniowana
add a note
User Contributed Notes 8 notes
eric at themepark dot com ¶
19 years ago
mindplay.dk ¶
11 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 = $version;
}
?>
insid0r at yahoo dot com ¶
15 years ago
Since this function considers 1 < 1.0 < 1.0.0, others might find this function useful (which considers 1 == 1.0):
<?php
//Compare two sets of versions, where major/minor/etc. releases are separated by dots.
//Returns 0 if both are equal, 1 if A > B, and -1 if B < A.
function version_compare2($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;
}
?>
Bob Ray ¶
8 years ago
Note that both leading and trailing spaces on your version numbers can break version_compare().
Tested on PHP 5.6.8:
<?php
echo "\nShould be 0";
echo "\n '1.0.0-pl' vs. '1.0.0-pl' ---> " . version_compare('1.0.0-pl', '1.0.0-pl');
echo "\n '1.0.0-pl' vs. ' 1.0.0-pl' ---> " . version_compare('1.0.0-pl', ' 1.0.0-pl');
echo "\n ' 1.0.0-pl' vs. '1.0.0-pl' ---> " . version_compare(' 1.0.0-pl', '1.0.0-pl');
echo "\n '1.0.0-pl' vs. '1.0.0-pl ' ---> " . version_compare('1.0.0-pl', '1.0.0-pl ');
echo "\n '1.0.0-pl ' vs. '1.0.0-pl' ---> " . version_compare('1.0.0-pl ', '1.0.0-pl');
echo "\n\nShould be 1";
echo "\n '1.1.1-pl' vs. '1.0.0-pl' ---> " . version_compare('1.1.1-pl', '1.0.0-pl');
echo "\n ' 1.1.1-pl' vs. '1.0.0-pl' ---> " . version_compare(' 1.1.1-pl', '1.0.0-pl');
echo "\n\nShould be -1";
echo "\n '1.0.0-pl' vs. '1.1.1-pl' ---> " . version_compare('1.0.0-pl', '1.1.1-pl');
echo "\n '1.0.0-pl' vs. ' 1.1.1-pl' ---> " . version_compare('1.0.0-pl', ' 1.1.1-pl');
/* Output
Should be 0
'1.0.0-pl' vs. '1.0.0-pl' ---> 0
'1.0.0-pl' vs. ' 1.0.0-pl' ---> 1
' 1.0.0-pl' vs. '1.0.0-pl' ---> -1
'1.0.0-pl' vs. '1.0.0-pl ' ---> 1
'1.0.0-pl ' vs. '1.0.0-pl' ---> -1
Should be 1
'1.1.1-pl' vs. '1.0.0-pl' ---> 1
' 1.1.1-pl' vs. '1.0.0-pl' ---> -1
Should be -1
'1.0.0-pl' vs. '1.1.1-pl' ---> -1
'1.0.0-pl' vs. ' 1.1.1-pl' ---> 1
*/
rogier ¶
12 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
opendb at iamvegan dot net ¶
16 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', '>')
arnoud at procurios dot nl ¶
19 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.
sam at wyvern dot non-spammers-remove dot com dot au ¶
19 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).
