PHP version comparison function version_compare() function

Recently, when I was working on a project, I remembered PHP version comparison. I checked Baidu and found the version_compare() function.

This is how the version_compare() function is described in the PHP manual:

version_compare() is used to compare two "PHP normalized" version number strings. This is helpful for writing programs that are only compatible with certain versions of PHP

This function first replaces _, - and + with a dot in the version string. It will also insert a dot before and after any non-number. In this way, something like '4.3.2RC1' will become '4.3.2.RC .1'. Next it splits the result, just like you would with explode('.', $ver) . It then compares the sections from left to right. If a section contains a specific version string, it will be processed in the following order: Any string not found in the list < dev < alpha = a < beta = b < RC = rc < # < pl =p. Not only can this method compare different version levels like '4.1' and '4.1.2', but it can also be specified to compare any version that contains PHP development status.

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

Return mixed

string $version1 - version 1 required

string $version2 - version 2 required

string $operator - understand it as an operator. Optional

That is, <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <> and ne.

If the third parameter is specified, boolean is returned. If the third parameter is not specified, the following three situations are returned:

Return -1 when the first version is lower than the second version

Return 0 when the first version is equal to the second version

When the first version is less than the second version, return 1

<?php
header('content-type:text/html;charset=utf-8');
/**
 * 判断php的版本是否在5.3.0以上
 */

echo '<pre class="brush:php;toolbar:false">';
 
//本人使用的版本为  5.2.17
echo 'PHP的当前版本为 '.PHP_VERSION."\n";

var_dump(version_compare(PHP_VERSION,'5.2.0'));

var_dump(version_compare(PHP_VERSION,'5.2.0','='));

var_dump(version_compare(PHP_VERSION,'5.3.0','ge'));

if(version_compare(PHP_VERSION,'5.3.0','ge')){

	echo '您的PHP版本大于5.3.0,当前版本为 '.PHP_VERSION;

}else{

	echo '您的PHP版本小于5.3.0,当前版本为 '.PHP_VERSION;

}

The result is as follows:

PHP的当前版本为 <span>5.2</span>.<span>17</span><span> int(</span><span>1</span><span>)
bool(</span><span>false</span><span>)
bool(</span><span>false</span><span>)
您的PHP版本小于5.</span><span>3.0</span>,当前版本为 <span>5.2</span>.<span>17</span>

​

The above introduces the PHP version comparison function version_compare() function, including the content of PHP version comparison and version_compare. I hope it will be helpful to friends who are interested in PHP tutorials.