Keeping dictionary keys of JSON Object in order in

问题:

I'm using the JSON-FRAMEWORK in objective C to parse a JSON object. When I call [jsonString JSONValue], I get back a dictionary, but the keys aren't in the same order as the JSON Object I'm parsing. Is there anyway to keep this order the same?

回答1:

In JSON objects, by definition, the order of the key-value pairs is not meaningful. The specification allows a JSON producer to permute them any way it want, even at random -- and does not require a parser to preserve the ordering. RFC 4627 says:

An object is an unordered collection of zero or more name/value pairs, where a name is a string and a value is a string, number, boolean, null, object, or array.

If you need the ordering to be preserved, what you have is not JSON, but a home-defined format that just happens to look superficially like JSON.