version_compare
Compares two "PHP-standardized" version number strings
Description
intbool version_compare(string $version1
, string $version2
, stringnull $operator
= null
)
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
-
An optional operator. 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, '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";
}
?>
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
- phpversion
- php_uname
- function_exists