(PHP 4 >= 4.1.0, PHP 5)
version_compare — Compares two "PHP-standardized" version number strings
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.
version1First version number.
version2Second 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.
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.
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";
}
?>
Note:
The
PHP_VERSIONconstant 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().