I have a json like:

var json = [{"Google":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Linkedin":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Uber":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Akamai":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Apple":[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]},
                {"Hulu":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"IBM":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Spotify":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Amazon":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}];

I want to iterate through it. json.length returns 9 => implying there are 9 key/value pairs in this json. How can I find key at index 0 and its corresponding value in javascript.

I tried using something like:

$.each(json, function(k, v) {
        //display the key and value pair
        alert(k + ' is ' + v);
    });

but here key is returning 1,2,3... and value as [object object]

I have a json like:

var json = [{"Google":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Linkedin":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Uber":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Akamai":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Apple":[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]},
                {"Hulu":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"IBM":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Spotify":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Amazon":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}];

I want to iterate through it. json.length returns 9 => implying there are 9 key/value pairs in this json. How can I find key at index 0 and its corresponding value in javascript.

I tried using something like:

$.each(json, function(k, v) {
        //display the key and value pair
        alert(k + ' is ' + v);
    });

but here key is returning 1,2,3... and value as [object object]

• javascript
• jquery
• json

• Your json var is an array that contains json object. – user3502626 Commented Apr 28, 2016 at 4:56

6 Answers 6

Use Array.prototype.forEach() to iterate through the array and Object.keys over iterated item to get all the keys of individual object.

var json = [{
  "Google": [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Linkedin": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Uber": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Akamai": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Apple": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Hulu": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "IBM": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Spotify": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}, {
  "Amazon": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
}];
json.forEach(function(item) {
  var keys = Object.keys(item);
  console.log(keys);
  //to get the values
  keys.forEach(function(key) {
    console.log(item[key]);
  })
});

How can I find key at index 0 and its corresponding value in javascript.

You can get all the key names in an object by using Object.keys method.

try

var key0 = Object.keys(json[0])[0];

this will give you key name at index 0.

And

value0 = json[0][key0];

This can be made more generic to iterate through entire json

json.forEach(function(val){
   var key = Object.keys(val)[0];
   var value = val[key];
   console.log( "key is " + key );
   console.log( "value is " + value );
});

You should consider re-formatting your JSON data.

I personally think it's good practice to give each value an appropriate "attribute" when using JSON Objects (Giving "Google" an attribute of "pany") for easier access to the values & readability.

EG:

var json = [{'pany':"Google",'values':[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Linkedin",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Uber",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Akamai",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Apple",'values':[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]},
            {'pany':"Hulu",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"IBM",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Spotify",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
            {'pany':"Amazon",'values':[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}];

Then, you can iterate through the values by using 2 $.each loops. One nested after the other.

$.each(json,function(key,val){

   var pany = val.pany;
   console.log('Below values belong to '+pany);

   $.each(val.values,function(k,v){
     var value = v;
     console.log(value);
   });

   console.log('End of values belonging to '+pany);
});

To find the key (I assume by key you mean the pany name) at index 0, you can access the json array with the index of 0 as such.

var pany = json[0].pany;
var valueArray = json[0].values;

something like this

var json = [{"Google":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Linkedin":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Uber":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Akamai":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Apple":[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]},
                {"Hulu":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"IBM":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Spotify":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Amazon":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}];

json.forEach(function(n){  
  Object.keys(n).forEach(function(x) { 
    document.writeln(x + ' is ' + n[x] + '</br>');  
  }) 
}) ;

Hope this will be useful

var json = [
                {"Google":[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Linkedin":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Uber":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Akamai":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Apple":[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]},
                {"Hulu":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"IBM":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Spotify":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},
                {"Amazon":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}
             ];

     json.forEach(function(key,value){
     var _getCurrentItem = key; // will give google:Array[18]....
     // Loop through this object to get its key & value
         for(var keys in _getCurrentItem){ 
         console.log('Key is ' + keys +' & its value' +_getCurrentItem[keys]);
     }) 

Check this Jsfiddle for working model

[] represents an array which means the keys are integers : 0 to (N-1) : N is the number of items in the array/list. i.e. : var t = ["Me", "You", "Them"]; where t[0] is "Me" and t[2] is "Them".

{} represents an object or associative array : an array with string keys. i.e. var t = {"firstperson" : "me", "secondperson" : "you", "thirdperson" : "them"}; where t["firstperson"] is "me".

So, in your data representation, you should have two loops, one within the other :

$.each(json, function(k, v) {
    //display the key and value pair
    $.each(v, function(k2, v2) {
            //display the key and value pair
            alert('json[' + k + '][' + k2 + '] = ' + v2);
        });
});