CODEWITHSUNDEEP
javascriptjsonparsing
Peter
Peter

Reputation: 5332

Basic JSON.parse question

I can't seem to access my objects.

after parsing the server string:

var json = JSON.parse(myJsonText):

I get the below with an alert:

alert(json.param1)

{"ID":17,"Name":"swimming pools","ParentID":4,"Path":""},
{"ID":64,"Name":"driveways","ParentID":4,"Path":""}

Now, I am trying to access ID and Name.

I have tried:

json.param1[0].ID
json.param1[0]["ID"]
json.param1[0][0]

And a lot of others that really don't make much sense such as: 

json[0].ID or 
json.param1.ID etc...

I am getting (for example, in the case of json.param1[0].ID):

param1.0.ID is null or not an object.

Any ideas?

Upvotes: 0

Views: 1185

Answers (5)

system PAUSE
system PAUSE

Reputation: 38550

Try this

// you already have this bit
var json = JSON.parse(myJsonText);
alert(json.param1);

// add this
var tmp_param1 = JSON.parse(json.param1);
json.param1 = tmp_param1;
alert(json.param1);  // should print [object, object] or similar

alert(json.param1[0].ID);  // should print "17"
alert(json.param1[0].Name);  // should print "swimming pools"

Upvotes: 2

Jonathan Lonowski
Jonathan Lonowski

Reputation: 123513

To compile and expand on all of the comments... ;)

Your first clue that something's wrong is your alert:

alert(json.param1)

Instead of getting:

{"ID":17,"Name":"swimming pools","ParentID":4,"Path":""},
{"ID":64,"Name":"driveways","ParentID":4,"Path":""}

You should be getting something similar to the following:

[object],[object]

Try alerting the typeof array element, itself:

alert(typeof json.param1[0]) //=> should say "object"

If you get anything besides "object", either the JSON isn't formatted correctly or the parser is failing.

One good clue as to which is wrong is if the original JSON looks like this:

{"param1" : [
  "{\"ID\":17,\"Name\":\"swimming pools\",\"ParentID\":4,\"Path\":\"\"}",
  "{\"ID\":64,\"Name\":\"driveways\",\"ParentID\":4,\"Path\":\"\"}"
]}

Then, it's probably the JSON that's broken. (Sorry ;)

On the other hand, if your JSON looks like this:

{"param1" : [
  {"ID":17,"Name":"swimming pools","ParentID":4,"Path":""},
  {"ID":64,"Name":"driveways","ParentID":4,"Path":""}
]}

Then, it's probably the parser.

Upvotes: 1

nickf
nickf

Reputation: 546263

if json.param1 is what you said it is, then json.param1[0].ID should work (and evaluate to "17").

If it's not working, could you show us the text you're parsing to generate the JSON object?

Upvotes: 0

Kyril
Kyril

Reputation: 3102

If you are receiving the raw JSON in the alert, then that would lead me to believe there is a problem w/ the JSON you are trying to parse.

Upvotes: 2

ChaosPandion
ChaosPandion

Reputation: 78282

That looks like invalid JSON. Try wrapping it in the brackets which makes it a valid array of JSON objects. Then access it by index.

[
    {"ID":17,"Name":"swimming pools","ParentID":4,"Path":""},
    {"ID":64,"Name":"driveways","ParentID":4,"Path":""}    
]

Upvotes: 2

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