Array of objects vs Object of Objects

Question

The issue is to decided the trade offs between following notations:

JSON based:

\"users\": {
    \"id1\": {
        \"id\": \"id1\",         


        

Answer 1

Along with all the above technical difference, I think there is a fundamental difference in the purpose and meaning of an Object and an Array.

1. The properties of an object DESCRIBE/DEFINE the object whereas

2. The elements of an array does NOT DESCRIBE/DEFINE the array, on the contrary the array defines what it's contents are. Do note - I am not talking about technical aspects. You can have any combinations technically but semantically each has its purpose.

   • For example a card holder. Each card does NOT DESCRIBE/DEFINE the card-holder. But the card holder does define it's purpose that it holds only cards/

   • An Object is used to represent an entity and its properties DESCRIBE/DEFINE the entity. Take the same example of a Card. A card has properties like color, number which DESCRIBE/DEFINE what the card is.

For your above example:

1. Each object which represents a person is defined by the properties id, firstName and lastName.

2. A list of these persons cannot be an object of objects because each id does not describe the object of objects. So

   "users":[ { "id":"id", "key2":"value2", "key3":"value3" }, { "id":"id", "key2":"value2", "key3":"value3" } ]

is a better representation than

"users": {
    "id1": {
        "id": "id1",
        "firstname": "firstname1",
        "lastname": "lastname1"
    },
    "id2": {
        "id": "id2",
        "firstaame": "firstname2",
        "lastname": "lastname2"
    }
}

even though technically you can use either. I hope i was able to convey(put into words) my thinking in the right manner.