PHP uses recursion to generate an article tree

Write recursive functions, you can consider caching, it is helpful to define a number of static variables to save the results of the last run. The approximate steps are: first to the database, to an array, then to the data into a tree-shaped array, and finally the tree-shaped array into HTML code. Now let's take a look at an example

Because of their own a technical station, to the main article, some of the article is a series, so want to classify these articles, the same category in one below.

Good database design, nothing but id,fatherid to classify, Fatherid on behalf of the parent is that article Id,id is the article's unique ID, the level is not limited, can be two layers, can be three layers. The Fatherid is a 0 representation of the top story.

PHP code, mainly recursive

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 This is the

Call:

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1	Category_tree (0)//First extract the top story

The above mentioned is the entire content of this article, I hope you can enjoy.