How does PHP read dat files?

How does PHP read dat files? How does PHP read two dat files, two data files, one storage name and one data access file? ------ Solution ------------------ first of all, you need to know how data is organized ------ solution ------------------ first, you need to know how data is organized ------ solution ------------------ read the php documentation, and the best way for PHP to read the dat file
How to read two dat files, two data files are associated, one storage name and one data access?

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First, you must know how data is organized.
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Discussion
First, you must know how data is organized.

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It's best to read the php document.

Http://php.net
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Is fopen the same as txt?