a web service returns the following nested json object:

{"age":"21-24","gender":"Male","location":"San Francisco, CA","influencer score":"70-79","interests":{"Entertainment":{"Celebrities":{"Megan Fox":{},"Michael Jackson":{}},},"Social Networks & Online Communities":{"Web Personalization": {},"Journals & Personal Sites": {},},"Sports":{"Basketball":{}},},"education":"Completed Graduate School","occupation":"Professional/Technical","children":"No","household_ine":"75k-100k","marital_status":"Single","home_owner_status":"Rent"}

i just want to iterate through this object without specifying property name, i tried the following code :

for (var data in json_data) {
    alert("Key:" + data + " Values:" + json_data[data]);
}

however it prints value as [object Object] if it's a nested value, is there any way to keep iterating deeper into nested values ?

a web service returns the following nested json object:

{"age":"21-24","gender":"Male","location":"San Francisco, CA","influencer score":"70-79","interests":{"Entertainment":{"Celebrities":{"Megan Fox":{},"Michael Jackson":{}},},"Social Networks & Online Communities":{"Web Personalization": {},"Journals & Personal Sites": {},},"Sports":{"Basketball":{}},},"education":"Completed Graduate School","occupation":"Professional/Technical","children":"No","household_ine":"75k-100k","marital_status":"Single","home_owner_status":"Rent"}

i just want to iterate through this object without specifying property name, i tried the following code :

for (var data in json_data) {
    alert("Key:" + data + " Values:" + json_data[data]);
}

however it prints value as [object Object] if it's a nested value, is there any way to keep iterating deeper into nested values ?

• javascript
• json

6 Answers 6

Try this:

function iter(obj) {
  for (var key in obj) {
    if (typeof(obj[key]) == 'object') {
      iter(obj[key]);
    } else {
      alert("Key: " + key + " Values: " + obj[key]);
    }
  }
}

BB: added + to prevent error.

You can do this recursively.

function alertobjectKeys(data) {
  for (var key in data) {
    if (typeof(data[key]) == "object" && data[key] != null) {
      alertobjectKeys(data[key]);
    } else {
      alert("Key:" + key + " Values:" + data[key]);
    }
  }
}

This of course requires recursion

(function(obj) {
  for (var key in obj) if (obj.hasOwnProperty(key)) {
    if (typeof obj[key] == 'object' && obj[key] !== null)
      arguments.callee(obj[key]);
    else 
      alert("Key: " + key + " Values: " + obj[key]);
  }
)(json_data));

function recursiveParse(variable) { 
    for (var key in variable) {
        if ((is_object(variable[key])) || (is_array(variable[key]))) {
            recursiveParse(variable[key]);
        } else {
            // Process variable here
        }
    }
}

Then just call that function with the parameter being the json data, it will parse through the remaining objects and arrays recursively.

You can always create a recursive function:

function alertObj(obj) {
    for (var data in obj) {
        if(typeof(obj[data]) === "object")
            alertObj(obj[data]);
        else
            alert("Key:" + data + " Values:" + obj[data]);
    }
}

As long as you aren't worried about recursing too far (which you probably don't need to with JSON objects).

You can also do this with a queue or stack (array) structure:

function alertObj_queue(obj) { // Breadth-first
    var arrPrint = [{key:"Object", data:obj}]; // Initialize array with original object

    for(var i = 0; i < arrPrint.length; i++) {
        if(typeof(arrPrint[i].data) === "object") {
            for(var k in arrPrint[i].data) { // Add each to end of array
                arrPrint.push({key: k, data: arrPrint[i].data[k]});
            }
            alert("Object key: " + arrPrint[i].key);
        } else {
            alert("Key:" + arrPrint[i].key + " Values:" + arrPrint[i].data);
        }
    }
}

function alertObj_stack(obj) { // Depth-first
    var arrPrint = [{key:"Object", data:obj}]; // Initialize array with original object

    while(arrPrint.length) {
        var o = arrPrint.pop();
        if(typeof(o.data) === "object") {
            for(var k in o.data) { // Add each to end of array
                arrPrint.push({key: k, data: o.data[k]});
            }
            alert("Object key: " + o.key);
        } else {
            alert("Key:" + o.key + " Values:" + o.data);
        }       
    }
}

I'm guessing that in your request (assuming it's Ajax) you aren't specifying the dataType to be returned as 'json'.