a question about eval in javascript

Question

thank you. here is the correct question:

{
    "VID":"60",
    "name":"\u4f1a\u9634",
    "requireLevel":"20",
    "levelMax":"5",
    "venationRequirement":"0",
    "description":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad8[Affect1]\u70b9",
    "cost":{"1":"240","2":"360","3":"400","4":"600","5":"720"},
    "difficult":{"1":"1024","2":"973","3":"921","4":"870","5":"819"},
    "affect":{"1":"200","2":"500","3":"900","4":"1400","5":"2000"},
    "descriptions":{
     "1":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad8200\u70b9",
     "2":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad8500\u70b9",
     "3":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad8900\u70b9",
     "4":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad81400\u70b9",
     "5":"\u6c14\u6d77\u4e0a\u9650\u63d0\u9ad82000\u70b9"
    }
}

i used json_encode() in php ,and ajax request to get the response text.

but when i use eval() to parse the response text. it's wrong.

moonshadow and james gregory has answered this question at the comments below.thank you again.

Answer 1

The [] syntax is explicitly for creating arrays whereas {} has a completely different meaning (it thinks you're trying to create a function/block)

Answer 2

so i can't use eval to parse a string like {{"a":1},{"b":2}}? right?

Answer 3

Your second one is wrong because you're evaluating a hash, for it to work you'd need to rewrite it to be something like:

var s = '{"first": {"a":1}, "second": {"b":2}}';

Answer 4

If your second example is an attempt to create an object with two nested objects, you're missing the names for the properties of the outer object, e.g.

var s = '{ "FirstSubObject" : {"a":1}, "SecondSubObject":{"b":2}}';

Answer 5

comments of this answer is the correct answer of this question.

Answer 6

Javascript gets a little confused about what, in what context, it is parsing. Prepend a '(' and append a ')' before passing the string to eval() to force it to parse the whole thing as an expression.

(Your question as posed is also missing labels for the outer associative array, as others have pointed out, however the sample data you've provided clarifies the actual problem).

Answer 7

Using json is a much better solution for this.