使用preg_replace向数组添加引号

Question

I have this array:

$array = '[[Smarties, 50g, 3, 1.99], 
          [M&Ms Peanut, 49g, 3, 1.99], 
          [Oreo Cookies, 300g, 1, 3.99], 
          [Pepsi, 355ml, 3, 1.29]]';

I need to use json_decode, so I need to find a way to surround the information inside in quotes like this:

[["Smarties", "50g", "3", "1.99"], 
["M&Ms Peanut", "49g", "3", "1"."99"], 
["Oreo Cookies", "300g", "1", "3.99"], 
["Pepsi", "355ml", "3", "1.29"]]

I tried using preg_replace, and this is what I'm currently getting (close, but it's separating the prices into two and also separating two-word names into two.):

[["Smarties", "50g", "3", "1"."99"], 
["M"&"Ms" "Peanut", "49g", "3", "1"."99"], 
["Oreo" "Cookies", "300g", "1", "3"."99"], 
["Pepsi", "355ml", "3", "1"."29"]]

I'm having a really hard time understanding preg_replace and I'm hoping someone might be able to help.

Is there a way to use the separating commas as guides to determine where to put the quotes?

Answer 1

For a somewhat crude, but context-aware regex one could use:

$str = preg_replace("~ [\[\],\s]*\K [^,\[\]]+ ~x", '"$0"', $str);
                           ↑             ↑
                        skip ][,    capture non-
                        + space   commas/brackets

Where the charclass before \K skips structural characters, and the second […] only finds anything but commas and brackets - which then is wrapped in quotes.