How to get the field name dynamically from the json object in javascript?

So this is the data I retrieved from api, and I would like to get more detail data from each of the filed in the object, like Name, Number, Select and so on.
But now the problem is the field name can be changed from the server side, so the ‘Name’ may become Title someday, and the Number can be changed to some other value in the future, so how should I do to specify them dynamically in the code instead of hard coded.
Any help would be appreciated!

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