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How can get a count with nested objects with a certain property?

Okay so I'm using angular to get a json saved to my computer to recreate a github gradebook.
I can get the data with my $http request but for the love of me all I want is to get a count of the number of issues with the label "Not Yet".
Here is the javascript:
$http.get('/api/github/repos/issues/all_issues/00All.json')
.then(function(response) {
console.log(response.data[0]);
var counter = 0;
for(var index = 0; index < response.data.length; index++) {
if(response.data[index].labels[0].name == "Not Yet") {
counter++;
};
};
console.log(counter);
});
That's the latest try, I also tried using lodash to get it earlier:
$http.get('/api/github/repos/issues/all_issues/00All.json')
.then(function(response) {
console.log(response);
mile.notYet.width = _.forEach(response.data, function(n){
var counter = 0;
if(_.result(_.find(n.labels[0], 'name')) == "Not Yet") {
counter++;
}
console.log(counter);
counter = ((counter/10) * 100) + '%';
});
});
This is a bit of the json data:
[
{
"url": "https://api.github.com/repos/TheIronYard--Orlando/2015--SUMMER--FEE/issues/11",
"labels_url": "https://api.github.com/repos/TheIronYard--Orlando/2015--SUMMER--FEE/issues/11/labels{/name}",
"comments_url": "https://api.github.com/repos/TheIronYard--Orlando/2015--SUMMER--FEE/issues/11/comments",
"events_url": "https://api.github.com/repos/TheIronYard--Orlando/2015--SUMMER--FEE/issues/11/events",
"html_url": "https://github.com/TheIronYard--Orlando/2015--SUMMER--FEE/issues/11",
"id": 73013825,
"number": 11,
"title": "00 -- Brace Yourself -- BEN GRIFFITH",
"user": {
"login": "Epicurean306",
"id": 11682684,
"avatar_url": "https://avatars.githubusercontent.com/u/11682684?v=3",
"gravatar_id": "",
"url": "https://api.github.com/users/Epicurean306",
"html_url": "https://github.com/Epicurean306",
"followers_url": "https://api.github.com/users/Epicurean306/followers",
"following_url": "https://api.github.com/users/Epicurean306/following{/other_user}",
"gists_url": "https://api.github.com/users/Epicurean306/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Epicurean306/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Epicurean306/subscriptions",
"organizations_url": "https://api.github.com/users/Epicurean306/orgs",
"repos_url": "https://api.github.com/users/Epicurean306/repos",
"events_url": "https://api.github.com/users/Epicurean306/events{/privacy}",
"received_events_url": "https://api.github.com/users/Epicurean306/received_events",
"type": "User",
"site_admin": false
},
"labels": [
{
"url": "https://api.github.com/repos/TheIronYard--Orlando/2015--SUMMER--FEE/labels/Not%20Yet",
"name": "Not Yet",
"color": "e11d21"
}
],
As you can see the labels property is an object, nested in an array, nested in an object, nested in an array, real lovely. Putting labels[0] results in an error for me each time and doesn't get me a count. Can anybody tell me where I'm messing up please? Thank you!

If you need a solution that includes lodash, which is much more performant than the native high order functions then you can try this solution below:
var size = _(response.data)
.pluck('labels')
.flatten()
.where({ name: 'Not Yet' })
.size();
UPDATE:
If you want it to be more reusable, you can save a reference for a cloned chained sequence and simply supply another array for that cloned sequence.
var data1 = [/*array from data1*/];
var data2 = [/*array from data2*/];
var notYetSequence = _(data1)
.pluck('labels')
.flatten()
.where({ name: 'Not Yet' });
notYetSequence.size(); // returns data 1 count
notYetSequence.plant(data2).size(); // returns data 2 count

You don't need lodash for the task
var cnt = response.data
.map(function(i) { return i.labels; })
// here we extract labels object only (and get an array of arrays of objects)
.map(function(i) { return i.filter(function(l) { return l.name == 'Not yet'; }).length; })
// then for every nested array we return a number of items with
// Not Yet names (and get an array of numbers)
.filter(function(c) { return c > 0; })
// then we filter issues that don't have one (and still get an array of numbers)
.length;
// and finally get length (which is a number)

As a comparison, a plain for loop looks like:
var data = response.data;
var count = 0;
var re = /not yet/i;
for (var a, i=0, iLen=data.length; i<iLen; i++) {
a = data[i].labels;
for (var j=0, jLen=a.length; j<jLen; j++) {
if (re.test(a[j].name)) ++count;
}
}
So really not a lot of code either way, the for loop will be compatible with every browser ever (though using xmlHTTPRequest means at least ed 3+) and fastest… untested of course. ;-)

Javascript Array of Objects and Unique Values

I have an array of objects that looks like this:
[
{"name":"Andrea","from":"USA","Food":"Candy"},
{"name":"Matt","from":"Taiwan","Food":"Chicken"},
{"name":"Roddy","from":"USA","Food":"Rice"},
{"name":"Andy","from":"Great Britain","Food":"Steak"},
];
Is there a way to get the list of all countries from the array above, and get rid of the repeated ones?
So from the list above, the list I am to obtain is:
["USA", "Taiwan", "Great Britain"]
Thank you!

Just loop over people and insert unique countries in a new array. Here is an example.
var countries = [];
var people = [
{"name":"Andrea","from":"USA","Food":"Candy"},
{"name":"Matt","from":"Taiwan","Food":"Chicken"},
{"name":"Roddy","from":"USA","Food":"Rice"},
{"name":"Andy","from":"Great Britain","Food":"Steak"},
];
for (var i = 0, l=people.length; i < l; i++) {
if(people[i] && people[i].from) {//ensure country exists
if (countries.indexOf(people[i].from) == -1) {//ensure unique
countries.push(people[i].from);
}
}
}

Yet another variant with reduce
var arr = [
{"name":"Andrea","from":"USA","Food":"Candy"},
{"name":"Matt","from":"Taiwan","Food":"Chicken"},
{"name":"Roddy","from":"USA","Food":"Rice"},
{"name":"Andy","from":"Great Britain","Food":"Steak"},
];
var countries = arr.reduce(function(acc, cur){
if(!acc.map[cur.from]){
acc.map[cur.from]=true;
acc.result.push(cur.from);
}
return acc;
}, {result:[], map:{}}).result;
var arr = [
{"name":"Andrea","from":"USA","Food":"Candy"},
{"name":"Matt","from":"Taiwan","Food":"Chicken"},
{"name":"Roddy","from":"USA","Food":"Rice"},
{"name":"Andy","from":"Great Britain","Food":"Steak"},
];
var countries = arr.reduce(function(acc, cur){
if(!acc.map[cur.from]){
acc.map[cur.from]=true;
acc.result.push(cur.from);
}
return acc;
}, {result:[], map:{}}).result;
document.getElementById('countries').innerHTML = countries.join();
<span id="countries"></span>

If you are already using the excellent Lodash library, the following will do it for you neatly in one line:
var uniqueCountries = _(dataArray).pluck('from').unique().value();
UnderscoreJS has similar functionality using chaining.
For D3.js, the following will do it:
var uniqueCountries = d3.set(dataArray.map(function (x) { return x.from; })).values();
Without doing the unique-ifying on the server and returning that data separately, there is no way to get around looping through all records at least once to do this. For 1000 records or so, though, this will still be very fast.
For plain JS, see other answers.

I'd loop over the Array and put the country into an array if it is not yet inside that array.

Is there a way to iterate and display the list of key value pairs of json using Handlebar.js

As Iam new to javascript, I found handleBar.js can be used to template with dynamic data.
I worked on a sample which worked fine and the json structure was simple and straight forward.
(function()
{
var wtsource = $("#some-template").html();
var wtTemplate = Handlebars.compile(wtsource);
var data = { users: [
{url: "index.html", name: "Home" },
{url: "aboutus.html", name: "About Us"},
{url: "contact.html", name: "Contact"}
]};
Handlebars.registerHelper('iter', function(context, options) {
var fn = options.fn, inverse = options.inverse;
var ret = "";
if(context && context.length > 0) {
for(var i=0, j=context.length; i<j; i++) {
ret = ret + fn($.extend({}, context[i], { i: i, iPlus1: i + 1 }));
}
} else {
ret = inverse(this);
}
return ret;
});
var temp=wtTemplate(data);
$("#content").html(temp);
})();
<script id="some-template" type="text/x-handlebars-template">
{{#iter users}}
<li>
{{name}}
</li>
{{/iter}}
</script>
How to iterate a json with the below structure ? Please do suggest the possible way for iterating and creating the template for the below json structure
var newData = { "NEARBY_LIST": {
"100": {
"RestaurantID": 100,
"ParentRestaurantID": 0,
"RestaurantName": "Chennai Tiffin",
"listTime": [{
"startTime": "10:00",
"closeTime": "23:30"
} ]
},
"101": {
"RestaurantID": 101,
"ParentRestaurantID": 0,
"RestaurantName": "Biriyani Factory",
"listTime": [{
"startTime": "11:00",
"closeTime": "22:00"
}]
}
}
};

Accessing the properties of an object has nothing to do with Handlebars. If you dealing with JSON and you wish to access it in general bracket or dot notation, you must first parse the JSON into a JavaScript object using the JSON.parse() function.
After this is done, you may access the properties as follows.
var property = newData['NEARBY_LIST']['100'].RestaurantName; // "Chennai Tiffin"
Here is a fiddle to illustrate.
http://jsfiddle.net/qzm0cygu/2/

I'm not entirely sure what you mean, but if your question is how you can use/read the data in newData, try this:
newData = JSON.parse(newData); //parses the JSON into a JavaScript object
Then access the object like so:
newData.NEARBY_LIST //the object containing the array
newData.NEARBY_LIST[0] //the first item (key "100")
newData.NEARBY_LIST[1] //the second item (key "101")
newData.NEARBY_LIST[0][0] //the first field of the first item (key "RestaurantID", value "100")
newData.NEARBY_LIST[0][2] //the third field of the first item (key "RestaurantName", value "Chennai Tiffin")
newData.NEARBY_LIST[0][3][0] //the first field of the fourth field of the first item (key "startTime", value "11:00")
I hope this was what you were looking for.
EDIT: as Siddharth points out, the above structure does assume you have arrays. If you are not using arrays you can access the properties by using their names as if they're in an associative array (e.g. newData["NEARBY_LIST"]["100"]. The reason I say "properties" and "as if" is because technically JavaScript doesn't support associative arrays. Because they are technically properties you may also access them like newData.NEARBY_LIST (but I don't recommend that in this case as a property name may not start with a number, so you would have to use a mix of the different notations).
On that note, I would recommend using arrays because it makes so many things easier (length checks, for example), and there are practically no downsides.
EDIT2: also, I strongly recommend using the same camelcasing conventions throughout your code. The way you currently have it (with half your properties/variables starting with capitals (e.g. "RestaurantName", "RestaurantID") and the other half being in lowerCamelCase (e.g. "listTime", "startTime")) is just asking for people (you or colleagues) to make mistakes.

What's the best way to query an array in javascript to get just the items from it I want?

I have an array like this (with just over 3000 objects instead of the 3 here):
items = [{name:'charlie', age:'16'}, {name:'ben', age:'18'}, {name:'steve', age:'18'}]
What's the best way to return an array with just the objects of people who are 18? So I want:
items = [{name:'ben', age:'18'}, {name:'steve', age:'18'}]
The best I can think of is this (using jQuery):
newArray = []
$.each(items, function(index, item) {
if(item.age=='18') {
newArray.push(item)
}
})
Considering that there's 3000 thousand objects, and also that I'll be doing that comparison up to fifty times in one go, that's a lot of looping. Is there a better way?

You can use pure javascript
var wanted = items.filter( function(item){return (item.age==18);} );
And if your browser does not support the 1.6 version of javascript you can find an implementation of the filter method at https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/filter
Update
Speedwise there is a huge varying (had an error in the test) difference from a normal loop (depending on browser).. Have a look at this little test i made at http://jsperf.com/array-filter-vs-loop/3

Get matched item and items using find() and filter() method
If you want first matched single item, use find() method which returns single object.
If you want all matched , use filter() method which returns array of objects.
let items = [{name:'charlie', age:'16'},
{name:'ben', age:'18'},
{name:'steve', age:'18'}]
let all = items.filter(item=> item.age==='18')
console.log(all);
let single = items.find(item=> item.age==='18')
console.log(single);

If you're going to do the search often it may be best to keep a version of your data in a form that is quick to access.
I've used underscore.js (http://documentcloud.github.com/underscore/) to make it easy for myself, but this code here will create an object that holds your data indexed by the age field.
You end up with something that looks like this:
{
"16": [
{
"name": "charlie",
"age": "16"
}
],
"18": [
{
"name": "ben",
"age": "18"
},
{
"name": "steve",
"age": "18"
}
]
}
The code:
var itemsByAge = _(items).reduce(function(memo, item) {
memo[item.age] = memo[item.age] || [];
memo[item.age].push(item);
return memo;
}, {});
alert(JSON.stringify(itemsByAge["18"]));

No matter which method you choose (items.filter or any "query language" for json), a for loop is inevitable.
If performance is a concern, I would recommend you to use pure javascript instead of libraries like jQuery which will add overheads to the whole processing as is evident here.
Thus, your code would look like:
var newArray = [];
for(var i=0;i<items.length;i++) {
var item = items[i];
if(item.age == '18') {
newArray.push(item);
}
});

making use of javascript magnificent function eval() which evaluates string as code at runtime, we can define a prototype method for Array type
Array.prototype.where = function (query) {
var newArray = [];
for(var i=0; i<this.length; i++) {
var item = this[i];
if(eval( "item" + query )) {
newArray.push(item);
}
}
return newArray;
};
and use it with any array, passing the query as string
var newArray= items.where('.age >= 18');

Use the filter method of the array, it calls the provided callbackfunction once for each element in an array.
array.filter(<callbackfucntion>[, <Object to use>])

once i had such problem and i solved it like this
1- create an array of array
2- each index create an Index record
e.g.
var pAry=[];
var cAry=[{name:'ben', age:'18'}, {name:'steve', age:'18'}]
pAry[17]=cAry;
This way when u require person with age 18, you will get on index 17.

Use a JSON array with objects with javascript

I have a function that will get a JSON array with objects. In the function I will be able to loop through the array, access a property and use that property. Like this:
Variable that I will pass to the function will look like this:
[{
"id": 28,
"Title": "Sweden"
}, {
"id": 56,
"Title": "USA"
}, {
"id": 89,
"Title": "England"
}]
function test(myJSON) {
// maybe parse my the JSON variable?
// and then I want to loop through it and access my IDs and my titles
}
Any suggestions how I can solve it?

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
.

This is your dataArray:
[
{
"id":28,
"Title":"Sweden"
},
{
"id":56,
"Title":"USA"
},
{
"id":89,
"Title":"England"
}
]
Then parseJson can be used:
$(jQuery.parseJSON(JSON.stringify(dataArray))).each(function() {
var ID = this.id;
var TITLE = this.Title;
});

By 'JSON array containing objects' I guess you mean a string containing JSON?
If so you can use the safe var myArray = JSON.parse(myJSON) method (either native or included using JSON2), or the usafe var myArray = eval("(" + myJSON + ")"). eval should normally be avoided, but if you are certain that the content is safe, then there is no problem.
After that you just iterate over the array as normal.
for (var i = 0; i < myArray.length; i++) {
alert(myArray[i].Title);
}

Your question feels a little incomplete, but I think what you're looking for is a way of making your JSON accessible to your code:
if you have the JSON string as above then you'd just need to do this
var jsonObj = eval('[{"id":28,"Title":"Sweden"}, {"id":56,"Title":"USA"}, {"id":89,"Title":"England"}]');
then you can access these vars with something like jsonObj[0].id etc
Let me know if that's not what you were getting at and I'll try to help.
M

#Swapnil Godambe
It works for me if JSON.stringfy is removed.
That is:
$(jQuery.parseJSON(dataArray)).each(function() {
var ID = this.id;
var TITLE = this.Title;
});

var datas = [{"id":28,"Title":"Sweden"}, {"id":56,"Title":"USA"}, {"id":89,"Title":"England"}];
document.writeln("<table border = '1' width = 100 >");
document.writeln("<tr><td>No Id</td><td>Title</td></tr>");
for(var i=0;i<datas.length;i++){
document.writeln("<tr><td>"+datas[i].id+"</td><td>"+datas[i].Title+"</td></tr>");
}
document.writeln("</table>");