Javascript how to parse JSON array

Question

I m using Sencha Touch  ExtJS  to get a JSON message from the server  The message I receive is this one       success   true   counters                    counter name    dsd            counter type    sds            counter unit    sds                        counter name    gdg            counter type    dfd            counter unit    ds                        counter name    sdsData            counter type    sds            counter unit       dd                               counter name    Stoc final            counter type    number                counter unit    litri                             counter name    Consum GPL            counter type    number                counter unit    litri                             counter name    sdg            counter type    dfg            counter unit    gfgd                        counter name    dfgd            counter type    fgf            counter unit    liggtggggri                             counter name    fgd            counter type    dfg            counter unit    kwfgf                               counter name    dfg            counter type    dfg            counter unit    dg                        counter name    gd            counter type    dfg            counter unit    dfg                   My problem is that I can t parse this JSON object so that i can use each of the counter objects   I m trying to acomplish that like this    var jsonData   Ext util JSON decode myMessage   for  var counter in jsonData counters         console log counter counter name        What am i doing wrong   Thank you

User · Answer

Not sure if my data matched exactly but I had an array of arrays of JSON objects, that got exported from jQuery FormBuilder when using pages.

Hopefully my answer can help anyone who stumbles onto this question looking for an answer to a problem similar to what I had.

The data looked somewhat like this:

var allData = 
[
    [
        {
            "type":"text",
            "label":"Text Field"
        }, 
        {
            "type":"text",
            "label":"Text Field"
        }
    ],
    [
        {
            "type":"text",
            "label":"Text Field"
        }, 
        {
            "type":"text",
            "label":"Text Field"
        }
    ]
]

What I did to parse this was to simply do the following:

JSON.parse("["+allData.toString()+"]")

User · Answer

Javascript has a built in JSON parse for strings  which I think is what you have   var myObject   JSON parse  my json string      to use this with your example would be   var jsonData   JSON parse myMessage   for  var i   0  i  lt  jsonData counters length  i          var counter   jsonData counters i       console log counter counter name       Here is a working example  EDIT  There is a mistake in your use of for loop  I missed this on my first read  credit to  Evert for the spot   using a for-in loop will set the var to be the property name of the current loop  not the actual data  See my updated loop above for correct usage  IMPORTANT  the JSON parse method wont work in old old browsers - so if you plan to make your website available through some sort of time bending internet connection  this could be a problem  If you really are interested though  here is a support chart  which ticks all my boxes

User · Answer

You should use a datastore and proxy in ExtJs  There are plenty of examples of this  and the JSON reader automatically parses the JSON message into the model you specified   There is no need to use basic Javascript when using ExtJs  everything is different  you should use the ExtJs ways to get everything right  Read there documentation carefully  it s good   By the way  these examples also hold for Sencha Touch  especially v2   which is based on the same core functions as ExtJs

User · Answer

In a for-in-loop the running variable holds the property name  not the property value   for  var counter in jsonData counters        console log jsonData counters counter  counter name       But as counters is an Array  you have to use a normal for-loop   for  var i 0  i lt jsonData counters length  i          var counter   jsonData counters i       console log counter counter name

User · Answer

Something more to the point for me    var jsontext      firstname   Jesper   surname   Aaberg   phone    555-0100   555-0120        var contact   JSON parse jsontext     document write contact surname          contact firstname     document write contact phone 1         Output       Aaberg  Jesper      555-0100      Reference    https   docs microsoft com en-us scripting javascript reference json-parse-function-javascript

User · Answer

This works like charm    So I edited the code as per my requirement  And here are the changes  It will save the id number from the response into the environment variable   var jsonData   JSON parse responseBody   for  var i   0  i  lt  jsonData data length  i          var counter   jsonData data i       postman setEnvironmentVariable  schID   counter id

User · Answer

Sencha way  for interacting with server data is setting up an Ext data Store proxied by a Ext data proxy Proxy  in this case Ext data proxy Ajax  furnished with a Ext data reader Json  for JSON-encoded data  there are other readers available as well   For writing data back to the server there s a Ext data writer Writers of several kinds   Here s an example of a setup like that       var store   Ext create  Ext data Store             fields                 counter name                counter type                counter unit                      proxy                type   ajax               url   data1 json                reader                    type   json                   idProperty   counter name                   rootProperty   counters                                    data1 json in this example  also available in this fiddle  contains your data verbatim  idProperty   counter name  is probably optional in this case but usually points at primary key attribute  rootProperty   counters  specifies which property contains array of data items   With a store setup this way you can re-read data from the server by calling store load    You can also wire the store to any Sencha Touch appropriate UI components like grids  lists or forms

User · Answer

Just as a heads up     var data   JSON parse responseBody     has been deprecated   Postman Learning Center now suggests  var jsonData   pm response json

User · Answer

This is my answer    lt  DOCTYPE html gt   lt html gt   lt body gt   lt h2 gt Create Object from JSON String lt  h2 gt   lt p gt  First Name   lt span id  fname  gt  lt  span gt  lt br gt   Last Name   lt span id  lname  gt  lt  span gt  lt br gt    lt  p gt    lt script gt  var txt      employees          firstName   John   lastName   Doe           firstName   Anna   lastName   Smith           firstName   Peter   lastName   Jones           var jsonData   eval        txt         var jsonData   JSON parse txt   for  var i   0  i  lt  jsonData employees length  i          var counter   jsonData employees i         console log counter counter name       alert counter firstName       lt  script gt   lt  body gt   lt  html gt

User · Answer

The answer with the higher vote has a mistake  when I used it I find out it in line  3    var counter   jsonData counters i     I changed it to    var counter   jsonData i  counters    and it worked for me  There is a difference to the other answers in line 3    var jsonData   JSON parse myMessage   for  var i   0  i  lt  jsonData counters length  i          var counter   jsonData i  counters      console log counter counter name

[javascript] Javascript how to parse JSON array

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