Why is there @foo and $ keys in JSON ?

[Magador]

It is known as the BadgerFish convention used to represent XML documents into JSON.

the @ sign before any key is used to indicate a property of the element as the $ represent the value of the element:

<alice charlie="David">
    Bob
</alice>

convert into:

{  
   "alice":{  
      "$":"Bob",
      "@charlie":"David"
   }
}

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