PHP版本如何编号？

Question

I am looking to upgrade WordPress on my server. WordPress 3.2 requires PHP 5.2.4 or greater. My server is running PHP 5.2.17. Looking at the release history on php.net, I see that:

1. 5.2.4 was released 30 August 2007
2. There is no listing for 5.2.17
3. 5.2.16 was released 16 December 2010
4. Release order with a few versions goes: 5.2.13, 5.3.2, 5.2.14, 5.3.3, 5.2.15

Two questions:

• What is the logic of this numbering system?
• Is PHP 5.2.17 "greater" than 5.2.4?

Answer 1

In short,

• 5.3.x > 5.2.y
• 5.2.(z+1) > 5.2.(z)

You can also expect periodical maintenance releases on both 5.2 and 5.3. This is why you can see 5.2.x releases appearing after 5.3.y releases.

Hope that helps,