Javascript - Nested JSON into Array with jQuery - javascript

i have a little problem, i am a beginner in programming. I want to work with the Erast API, a Formula 1 API. I want to get all the drivers who won single races, the request is the following:
http://ergast.com/api/f1/current/results/1.json
Structure of the return values:
Problem is, that i dont know how to parse the JSON into a JS Array, I thought something like that:
var names = [];
var index = 0;
$.getJSON("http://ergast.com/api/f1/current/results/1.json", function(data, status) {
$.each(data.MRData.RaceTable.Races, function(name, value) {
//names.push(value.Results[0].Driver.givenName + " " + value.Results[0].Driver.familyName));
obj = $.parseJSON(value);
names.push(obj.Results[0].Driver.givenName);
//console.log(value.Results[0].Driver.givenName+ " " + value.Results[0].Driver.familyName);
});
});
If anyone knows the answer, would appreciate hearing from you

There is no need to parse JSON in the loop: jQuery has already decoded the JSON when it got the response in its implementation of $.getJSON.
So you can do this (also using map()):
$.getJSON("http://ergast.com/api/f1/current/results/1.json", function(data, status) {
var names = data.MRData.RaceTable.Races.map(function(value) {
return value.Results[0].Driver.givenName;
});
console.log(names);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Related

Complex JSON obj and jQuery or Javascript map to specific key, value

I am banging my head trying to figure this out. And it should not be this hard. I am obviously missing a step.
I am pulling data from: openaq.org
The object I get back is based on a JSON object.
For now, I am using jQuery to parse the object and I am getting to the sub portion of the object that hold the specific parameter I want but I can't get to the specific key,value pair.
The object does not come back in the same order all the time. So when I tried to originally set up my call I did something like
obj.results.measurements[0].
Well since the obj can come back in an random order, I went back to find the key,value pair again and it was the wrong value, throwing my visual off.
That said, I have looked at use jQuery's find() on JSON object and for some reason can not get what I need from the object I am given by openaq.org.
One version of the object looks like this:
{"meta":{"name":"openaq-api","license":"CC BY 4.0d","website":"https://u50g7n0cbj.execute-api.us-east-1.amazonaws.com/","page":1,"limit":100,"found":1},"results":[{"location":"Metro Lofts","city":null,"country":"US","coordinates":{"latitude":39.731,"longitude":-104.9888},"measurements":[{"parameter":"pm10","value":49.9,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"pm1","value":24,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"um100","value":0,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um025","value":0.28,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um010","value":4.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"pm25","value":41.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"}]}]}
I am trying to get the "pm25" value.
The code I have tried is this:
function getAirQualityJson(){
$.ajax({
url: 'https://api.openaq.org/v2/latest?coordinates=39.73915,-104.9847',
type: 'GET',
dataType: "json"
// data: data ,
}).done(function(json){
console.log("the json is" + JSON.stringify(json));
console.log("the json internal is" + JSON.stringify(json.results));
var obj = json.results;
var pm25 = "";
//console.log(JSON.stringify(json.results.measurements[0]["parameter"]));
$.each(json.results[0], function(i,items){
//console.log("obj item:" + JSON.stringify(obj[0].measurements));
$.each(obj[0].measurements, function(y,things){
//console.log("each measurement:" + JSON.stringify(obj[0].measurements[0].value));//get each measurement
//pm 2.5
//Can come back in random order, get value from the key "pm25"
// pm25 = JSON.stringify(obj[0].measurements[2].value);
pm25 = JSON.stringify(obj[0].measurements[0].value);
console.log("pm25 is: " + pm25); // not right
});
});
//Trying Grep and map below too. Not working
jQuery.map(obj, function(objThing)
{ console.log("map it 1:" + JSON.stringify(objThing.measurements.parameter));
if(objThing.measurements.parameter === "pm25"){
// return objThing; // or return obj.name, whatever.
console.log("map it:" + objThing);
}else{
console.log("in else for pm25 map");
}
});
jQuery.grep(obj, function(otherObj) {
//return otherObj.parameter === "pm25";
console.log("Grep it" + otherObj.measurements.parameter === "pm25");
});
});
}
getAirQualityJson();
https://jsfiddle.net/7quL0asz/
The loop is running through I as you can see I tried [2] which was the original placement of the 'pm25' value but then it switched up it's spot to the 3rd or 4th spot, so it is unpredictable.
I tried jQuery Grep and Map but it came back undefined or false.
So my question is, how would I parse this to get the 'pm25' key,value. After that, I can get the rest if I need them.
Thank you in advance for all the help.
You can use array#find and optional chaining to do this,
because we are using optional chaining, undefined will be returned if a property is missing.
Demo:
let data = {"meta":{"name":"openaq-api","license":"CC BY 4.0d","website":"https://u50g7n0cbj.execute-api.us-east-1.amazonaws.com/","page":1,"limit":100,"found":1},"results":[{"location":"Metro Lofts","city":null,"country":"US","coordinates":{"latitude":39.731,"longitude":-104.9888},"measurements":[{"parameter":"pm10","value":49.9,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"pm1","value":24,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"um100","value":0,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um025","value":0.28,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um010","value":4.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"pm25","value":41.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"}]}]}
let found = data?.results?.[0]?.measurements?.find?.(
({ parameter }) => parameter === "pm25"
);
console.log(found);
You can iterate over measurements and find the object you need:
const data = '{"meta":{"name":"openaq-api","license":"CC BY 4.0d","website":"https://u50g7n0cbj.execute-api.us-east-1.amazonaws.com/","page":1,"limit":100,"found":1},"results":[{"location":"Metro Lofts","city":null,"country":"US","coordinates":{"latitude":39.731,"longitude":-104.9888},"measurements":[{"parameter":"pm10","value":49.9,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"pm1","value":24,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"},{"parameter":"um100","value":0,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um025","value":0.28,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"um010","value":4.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"particles/cm³"},{"parameter":"pm25","value":41.1,"lastUpdated":"2021-08-09T20:49:38+00:00","unit":"µg/m³"}]}]}';
const json = JSON.parse(data);
let value = null;
const measurements = json?.results?.[0]?.measurements ?? null;
if(measurements)
for (const item of measurements)
if (item.parameter === 'pm25') {
value = item.value;
break;
}
if (value) {
// here you can use the value
console.log(value);
}
else {
// here you should handle the case where 'pm25' is not found
}

Parsing JSON to something usable

I know there are 1 million and 1 questions on this, but I cannot seem to find an answer.
I am receiving data via PHP as such
echo json_encode($result);
From a typical MYSQL query.
I get the result back like this in the console.
[{"id" : "1", "name" : "bob"}]
I am trying to use $.each to iterate through this so I can process my results but I only get errors, undefineds or 0[object Object].. things like that.
My goal is to append each value to a input box (retrieving data from a table to put into an edit box).
$.post('getstuff.php', { id : id } function(data){
$.each(data), function(k,v){
$('input[name= k ]').val(v);
});
});
As you can see i was hoping it was as simple as a key=>value pair but apparantly not. I have tried parsing, stringifiying.. really I am lost at this point. I also cannot tell $.post that I am using JSON because I am using a more arbitrary function, but am just posting that as my example.
Edit
var retrievedData = JSON.parse(data);
$.each(retrievedData, function(k,v){
for (var property in retrievedData) {
if (retrievedData.hasOwnProperty(property)) {
console.log(k);
console.log(v);
console.log(property);
//$('input[name= k ]').val(v);
}
}
});
In your second code sample, retrievedData is an array, which you iterate using jQuery $each...
$.each(retrievedData, function(k, v) {
OK so far. But then you try to iterate retrievedData again like an object, which it isn't. This is why you are getting undefined messages in the console
for (var property in retrievedData) {
if (retrievedData.hasOwnProperty(property)) {
console.log(k);
console.log(v);
console.log(property);
//$('input[name= k ]').val(v);
}
}
On the inner loop you should be iterating v not retrievedData. On each pass of $each v will be an object.Try this:
$.each(retrievedData, function(k,v){
for (var key in v) {
if (v.hasOwnProperty(key)) {
console.log("key: " + key);
console.log("value: " + v[key]);
}
}
});
You should do some type checking that v is an object first and catch any errors.
Use either :
$.ajax({
'dataType' : 'json'
});
Or
$.getJSON
Or if you want to use $.post, just do in your success function :
var good_data = JSON.parse(data);
$.each(good_data, function(k,v) {
$('input[name= k ]').val(v);
});
Answering your question based on your comments on other answer.
My assumption is you are getting data as JSON,if not you need to parse it,for that you can use JSON.parse(string).
Here I'm using Underscore.js
var data=[{"id" : "1", "name" : "bob"}]
$(data).each(function(ind,obj){
var keys=_.keys(obj);
$(keys).each(function(i,ke){
console.log(ke)
console.log(obj[ke]);
})
});
Here is JSFiddle of working code
First you need to define you're expecting JSON in your POST request - http://api.jquery.com/jQuery.post/
Then you need to iterate through the response.
$.post('getstuff.php', { id : id } function(data){
//Assuming you get your response as [{"id" : "1", "name" : "bob"}], this is an array
//you need to iterate through it and get the object and then access the attributes in there
$.each(data), function(item){
$('input[name=' + item.name + ']').val(item.id);
});
}, 'json');
EDIT
If you want to iterate over the properties of the objects returned, you need to put another loop inside the $.each
for (var property in item) {
if (object.hasOwnProperty(property)) {
// do stuff
}
}
More about it here - Iterate through object properties
EDIT 2
To address the solution you've posted. You've used the wrong variable names. Here's a working fiddle - http://jsfiddle.net/EYsA5/
var $log = $('#log');
var data = '[{"id" : "1", "name" : "bob"}]'; //because we're parsing it in the next step
var retrievedData = JSON.parse(data);
for (var parentProp in retrievedData) { //this gets us each object in the array passed to us
if (retrievedData.hasOwnProperty(parentProp)) {
var item = retrievedData[parentProp];
for (var property in item) { //this gives us each property in each object
if (item.hasOwnProperty(property)) {
console.log(item[property]);
$log.prepend("<br>");
$log.prepend("Property name is - " + property);
$log.prepend("<br>");
$log.prepend("Value of property is - " + item[property]);
//do stuff
}
}
}
};

Printing JSON Dictionary in JavaScript

I am getting the data from an API using JavaScript.
The statement console.log(json[0]) gives the result:
{"id":"1","username":"ghost","points":"5","kills":"18","xp":"10","diamonds":"0","level":"1","missionscomplete":"1"}
Now I am trying to print the individual elements of this dictionary. How do I do this ? My code is below:
function loadLeaderboard(){
$.get("http://localhost:8888/l4/public/api/v1/getLeaderboard",function(data){
var json = $.parseJSON(data);
console.log(json[0]);
$.each(json[i], function(key, data) {
console.log(key + ' -> ' + data);
});
});
}
EDIT:
The value of data as returned by the API is
["{\"id\":\"1\",\"username\":\"ghost\",\"points\":\"5\",\"kills\":\"18\",\"xp\":\"10\",\"diamonds\":\"0\",\"level\":\"1\",\"missionscomplete\":\"1\"}","{\"id\":\"2\",\"username\":\"seconduser\",\"points\":\"0\",\"kills\":\"3\",\"xp\":\"0\",\"diamonds\":\"0\",\"level\":\"0\",\"missionscomplete\":\"0\"}","{\"id\":\"3\",\"username\":\"goat\",\"points\":\"12\",\"kills\":\"13\",\"xp\":\"14\",\"diamonds\":\"10\",\"level\":\"10\",\"missionscomplete\":\"4\"}"]
The value in json after the operation var json = $.parseJSON(data); is
["{"id":"1","username":"ghost","points":"5","kills":…diamonds":"0","level":"1","missionscomplete":"1"}", "{"id":"2","username":"seconduser","points":"0","ki…diamonds":"0","level":"0","missionscomplete":"0"}", "{"id":"3","username":"goat","points":"12","kills":…amonds":"10","level":"10","missionscomplete":"4"}"]
You can just use stringify method of JSON-
console.log(JSON.stringify(json[0]));
Update
Your JSON data is a mess. It's not in the format you want. It should be an array of objects, but instead it is an array of strings, where each of those strings is the JSON representation of one of your user objects.
You could decode this in your JavaScript code, but you shouldn't have to. The JSON API should be fixed to generate a reasonable JSON object.
I don't know what language your server code is in, but it must be doing something like this pseudocode:
array = []
for each userObject in leaderBoard:
userJson = toJSON( userObject )
array.push( userJson )
jsonOutput = toJSON( array )
Instead, the code should look more like this:
array = []
for each userObject in leaderBoard:
array.push( userObject )
jsonOutput = toJSON( array )
In other words, the way to generate the JSON you want in most languages is to create an object or array with the structure you need, and then call the language's toJSON function (or whatever function you use) on that object or array. Let it generate all of the JSON in one fell swoop. Don't generate JSON for each individual element of your array and then generate JSON again for the entire array as a whole. That gives you an array of strings where you want an array of objects.
Original answer
What you're asking for is not what you really want to do.
Your JSON response returns an array of user objects, correct? That's why json[0] is a single object.
You probably want to loop over that array, but you don't loop over the individual objects in the array. You simply reference their properties by name.
Also, instead of using $.get() and $.parseJSON(), you can use $.getJSON() which parses it for you.
And one other tip: don't put the hostname and port in your URL. Use a relative URL instead, and then you can use the same URL in both development and production.
So for test purposes, let's say you want to log the id, username, and points for each user in your leaderboard JSON array. You could do it like this:
function loadLeaderboard() {
var url = '/l4/public/api/v1/getLeaderboard';
$.getJSON( url, function( leaders ) {
// leaders is an array of user objects, so loop over it
$.each( leaders, function( i, user ) {
// get the properties directly for the current user
console.log( user.id, user.username, user.points );
});
});
}
json[0] is an object, so you want to loop over the keys:
var o = json[0];
for (var key in o) {
if (o.hasOwnProperty(key)) {
console.log(key, o[key]);
}
}
Working fiddle: http://jsfiddle.net/UTyDa/
jQuery.each() is probably the easiest way, check this out: http://api.jquery.com/jQuery.each/
eg
$.each(json[0], function(key, data) {
console.log(key + ' -> ' + data);
});
EDIT:
What's the result of the following?
function loadLeaderboard(){
$.get("http://localhost:8888/l4/public/api/v1/getLeaderboard",function(data){
var json = $.parseJSON(data);
console.log(json[0]);
for(var i = 0; i < json.length; i++) {
$.each(json[i], function(key, data) {
console.log(key + ' -> ' + data);
});
}
});
}
EDIT 2: 'data' returned as array.
function loadLeaderboard(){
$.get("http://localhost:8888/l4/public/api/v1/getLeaderboard", function(data){
for(var i = 0; i < data.length; i++) {
var json = $.parseJSON(data[i]);
console.log('Data for index: ' + i);
$.each(json, function(key, val) {
console.log(key + ' -> ' + val);
});
}
});
}

Javascript split is not a function

Hey friends i am using javascript sdk to post on users friends wall with jQuery facebook multi friend selector however i am getting this error friendId.split is not a function. Here is my code
function recommendToFriend(pic, url, friendId, fromName)
{
alert(friendId);
var friendList ;
pFriend = new Array();
pFriend = friendId.split(',');
for( x in pFriend )
{
alert(pFriend[x]);
var publish = {
method:'feed',
picture:pic,
link:url,
name:'SHARP Product Recommend',
caption: fromName + 'has recommend a product to you via Sharp Expert lounge',
};
FB.api('/'+pFriend[x]+'/feed', 'post', publish, function(resp) {
if( !response || response.error )
alert('Unable to share');
else
alert('Successfully posted to firends wall');
});
}
}
In alert box i got comma seperated friend ids so i use split function post on each users wall seperately i dont know whats wrong here please help me
Most probably friendID is already an array. If you call alert the array is converted to a string and becomes a comma separated list of values.
Note that converting an array to a string is not the same as calling JSON.stringify (where you get also brackets and double quotes around elements when they're strings)
The JavaScript split() function is for the type string ie for eg.
var friendid='1,34,67';
As VisioN says, when you alert an array you get comma separated values.
You can traverse JS Objects like this
for (var key in friendid) {
var obj = friendid[key];
for (var prop in obj) {
alert(prop + " = " + obj[prop]);
}
}
Hope this helps
alternate
for( var x in friendId )
{
alert(friendId[x]); // this would be your desired value
}

How to loop through an JSON associative array in javascript?

I'm getting a JSON response from the server and i have to loop through the array in javascript and get the values. But I cant seem to loop throught it.
The JSON response of the array looks like this:
{
   "1": "Schools",
   "20": "Profiles",
   "31": "Statistics",
   "44": "Messages",
   "50": "Contacts"
}
I just want to loop through it to get the ID and Name and populate some values on the page.
I have tried:
$.each(response, function(key, value) {
alert(key + ' ' + value);
});
// and
for (var key in response) {
alert(key + ' ' + response[key]);
}
But neither give the right values.
Thanks in advance for any help.
Reply:
Hi,
The response I'm getting with the second loop is:
0 {
1 "
2 1
3 "
4 :
5 "
6 S
etc etc
So that means its going through the whole response as a string and spliting it as key/value.
Thanks
Your problem is that you are not parsing the JSON string. Therefore, your foreach is going through the characters in the JSON string.
// If you are using jQuery.ajax, you can just set dataType to 'json'
// and the following line will be done for you
var obj = jQuery.parseJSON( response );
// Now the two will work
$.each(obj, function(key, value) {
alert(key + ' ' + value);
});
for (var key in obj) {
alert(key + ' ' + response[key]);
}
var response = {"1":"Schools","20":"Profiles","31":"Statistics","44":"Messages","50":"Contacts"};
for (var i in response) {
console.log(i + ' ' + response[i]);
}
Works just fine, how are you getting your response var?
You don't need to do like that, dealing with string is a boring job. You can make a object through the response.
1:json = eval(xmlHttp.responseText);
but this is unsafe in some degree.
json = JSON.parse(xmlHttp.responseText, function(key,value){// can do some other stuff here.});
then you can operate the variable as a normal object like this obj.a or obj["a"].
May this will help you.
http://jsfiddle.net/sG5sF/
jQuery.each works fine. So is for-each loop
http://jsfiddle.net/TfjrS/
Both of them work as they should. You might have errors in other parts of your code. Is the response variable set correctly to the JSON object given in your question? Are you checking the response statusCode? it should be 200 for a successful response?
Consider looking at How can I parse a JavaScript object with jQuery for a possible answer.
You can use for-in construct in pure Javascript. Of course, you need to be careful that you're only looking at the object's own properties (libraries like Prototype tend to pollute):
for(var key in response) {
if(response.hasOwnProperty(key)) {
...
}
}
EDIT
Are you using jQuery.ajax? What's the dataType value? It should be json. This might be why your response is being interpreted as a string. Also, when you console.log response, does it show up as a string or an object?

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