Case Code Analysis of PHP Infinite level Classification

This article mainly explains the "case code analysis of PHP infinite level classification". The content of the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "case code analysis of PHP infinite level classification".

Main idea: first look at the third and fourth lines, the value of the parent class ID (PARENTID) is 1, indicating that it belongs to the subclass of id=1, while the first and second lines because it is a first-level classification, there is no superior classification, so the value of the parent class ID (PARENTID) is 0, indicating the primary classification, and then the infinite level classification is realized by analogy. The end result is:

├ first level classification A

├─┴ second-level classification A

├─┴ second level classification B

├ first-level classification B

Then there is the program, where PHP is used as the description language, which can be easily changed into other languages, because the principle is similar, it is just a recursion.