On the outermost level, a JSON object starts with a { and end with a }.

Sample data:

{
    "cars": {
        "Nissan": [
            {"model":"Sentra", "doors":4},
            {"model":"Maxima", "doors":4},
            {"model":"Skyline", "doors":2}
        ],
        "Ford": [
            {"model":"Taurus", "doors":4},
            {"model":"Escort", "doors":4}
        ]
    }
}

If the JSON is assigned to a variable called data, then accessing it would be like the following:

data.cars['Nissan'][0].model   // Sentra
data.cars['Nissan'][1].model   // Maxima
data.cars['Nissan'][2].doors   // 2

for (var make in data.cars) {
    for (var i = 0; i < data.cars[make].length; i++) {
        var model = data.cars[make][i].model;
        var doors = data.cars[make][i].doors;
        alert(make + ', ' + model + ', ' + doors);
    }
}

Another approach (using an associative array for car models rather than an indexed array):

{
    "cars": {
        "Nissan": {
            "Sentra": {"doors":4, "transmission":"automatic"},
            "Maxima": {"doors":4, "transmission":"automatic"}
        },
        "Ford": {
            "Taurus": {"doors":4, "transmission":"automatic"},
            "Escort": {"doors":4, "transmission":"automatic"}
        }
    }
}

data.cars['Nissan']['Sentra'].doors   // 4
data.cars['Nissan']['Maxima'].doors   // 4
data.cars['Nissan']['Maxima'].transmission   // automatic

for (var make in data.cars) {
    for (var model in data.cars[make]) {
        var doors = data.cars[make][model].doors;
        alert(make + ', ' + model + ', ' + doors);
    }
}

Edit:

Correction: A JSON object starts with { and ends with }, but it's also valid to have a JSON array (on the outermost level), that starts with [ and ends with ].

Also, significant syntax errors in the original JSON data have been corrected: All key names in a JSON object must be in double quotes, and all string values in a JSON object or a JSON array must be in double quotes as well.

See:

• JSON specification
• JSONLint - The JSON validator

This isn't a single JSON object. You have an array of JSON objects. You need to loop over array first and then access each object. Maybe the following kickoff example is helpful:

var arrayOfObjects = [{
  "id": 28,
  "Title": "Sweden"
}, {
  "id": 56,
  "Title": "USA"
}, {
  "id": 89,
  "Title": "England"
}];

for (var i = 0; i < arrayOfObjects.length; i++) {
  var object = arrayOfObjects[i];
  for (var property in object) {
    alert('item ' + i + ': ' + property + '=' + object[property]);
  }
  // If property names are known beforehand, you can also just do e.g.
  // alert(object.id + ',' + object.Title);
}

If the array of JSON objects is actually passed in as a plain vanilla string, then you would indeed need eval() here.

var string = '[{"id":28,"Title":"Sweden"}, {"id":56,"Title":"USA"}, {"id":89,"Title":"England"}]';
var arrayOfObjects = eval(string);
// ...

To learn more about JSON, check MDN web docs: Working with JSON .

you are calling SaveProduct(BillNo, Pname, Pqty, Pcost); after the for loop.so you are getting last index values.Make sure your method should be inside the loop.

    for (int i = 0; i < jsonArray.length(); i++) {
                                JSONObject jsonObject2 = jsonArray.getJSONObject(i);
                                ProductName = jsonObject2.getString("product_name");
                                ProductQTY = jsonObject2.getString("product_quantity");
                                ProductCost = jsonObject2.getString("product_cost");

SaveProduct(BillNo, ProductName, ProductQTY, ProductCost);
                            }

Give this a try:

$json = '
{
   "article_details":[  
      {  
         "article_code ":"000000000300028156 ",
         "diff_amnt ":"1 "
      },
      {  
         "article_code ":"000000000300028174 ",
         "diff_amnt ":"1 "
      },
      {  
         "article_code ":"000000000300028126 ",
         "diff_amnt ":"1 "
      }
   ],
   "article":[  
      {  
         "article_code ":"000000000300028156 ",
         "diff_amnt ":"1 "
      },
      {  
         "article_code ":"000000000300028174 ",
         "diff_amnt ":"1 "
      },
      {  
         "article_code ":"000000000300028126 ",
         "diff_amnt ":"1 "
      }
   ]
}';

$key = 'article_code '; // Since your key is 'article_code ' but not 'article_code', I have to do this
$dataObject = json_decode($json);
echo $dataObject->article_details[0]->$key; // This will out put: 000000000300028156 
$dataArray = json_decode($json, true);
echo $dataArray['article_details'][0]['article_code ']; // This will out put: 000000000300028156