How JSON in an array forms a two-dimensional JSON array

How JSON in an array forms a two-dimensional JSON array
This post was last edited by qq_27264201 on 2015-04-10 19:30:27

I have formed different JSON arrays of different classifications of the database, placed in array arrays, and now how to synthesize two JSON arrays into a two-dimensional JSON array.
My question now is that echo $array [0] and Echo $array [1] can be implemented, respectively, as a JSON array, but the echo $array has no way of printing. And why is there a backslash when we form a two-dimensional JSON? If you can, want to give a format
------to solve the idea----------------------
All in JSON, or all in numbers.

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