JSON 面试题与答案

Question: Compare JSON with JavaScript.

Answer: � JSON is a subset of the object literal notation of JavaScript
> JSON can be used in the JavaScript language with no muss or fuss
Example: JSON Object
var myJSONObject = {"bindings": [ {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"},
{"ircEvent": "PRIVMSG", "method": "deleteURI", "regex": "^delete.*"},
{"ircEvent": "PRIVMSG", "method": "randomURI", "regex": "^random.*"}
]
};
� In this example, a JSON JavaScript object is created
containing a single member "bindings", which contains
an array containing three objects, each containing
"ircEvent", "method", and "regex" members
� Members can be retrieved using dot or subscript
operators myJSONObject.bindings[0].method // "newURI"
Text to Object Conversion in
JavaScript code
var myObject = eval('(' + myJSONtext + ')');
� To convert a JSON text into an JSON object, use
the eval() function > eval() invokes the JavaScript compiler
> Since JSON is a proper subset of JavaScript, the compiler will
correctly parse the text and produce an object structure