Develop Reference

How to iterate through an array stored in Local Storage JavaScript?

In this application I am getting this information from users in an HTML form: var orderName, trackingNumber, price the user is updating these dynamically. Then I'm storing them in an array, converting it to json format, and keeping the orderName variable (which the user gave earlier) as the local storage key,
var myArray = [];
myArray.push(orderName, trackingNumber,price);
var JsonOrder = JSON.stringify(myArray );
localStorage.setItem(orderName,JsonOrder );
Now I want to display all the orders and their information. One page with all the orders listed, and the orderName should be a HYPERLINK that takes user to a page with information on just that order.
Here is what I'm doing to loop through the array:
var savedOrders = JSON.parse(localStorage.getItem('orderName'));
var orderName;
var trackingNumber;
var price;
for (var key in savedOrders ) {
orderName = savedOrders[key][0];
trackingNumber = savedOrders[key][1];
price = savedOrders[key][2];
}
This isn't working?

simply do
let JsonOrder = JSON.stringify( [orderName, trackingNumber, price] );
localStorage.setItem('someName',JsonOrder );
//---
let orderName, trackingNumber, price;
[orderName, trackingNumber, price] = JSON.parse(localStorage.getItem('someName'));

I found an answer here:
// Get the existing data
var existing = localStorage.getItem('myFavoriteSandwich');
// If no existing data, create an array
// Otherwise, convert the localStorage string to an array
existing = existing ? existing.split(',') : [];
// Add new data to localStorage Array
existing.push('tuna');
// Save back to localStorage
localStorage.setItem('myFavoriteSandwich', existing.toString());
from https://gomakethings.com/how-to-update-localstorage-with-vanilla-javascript/
I think there is a better way then to use split since what if the user enters a [] or , as their input?But so far this works just not a good method.

How to create multiple objects based on dynamic data?

Basically what i'm doing, is trying to create my own steam market JSON, by HTML parsing.
Example of how I'm currently doing that :
var url = 'http://steamcommunity.com/market/search?appid=730'
var itemDiv = $("<div></div>")
$.get(url).success(function(r){
data = $(r).find('stuff i need')
itemDiv.append(data)
})
and now say I wanted to find names of the items in the div, i would do something like :
itemDiv.find('x').each(function(){
var name = $(this).find("y").text()
// console.log(name) [or do whatever is needed ect]
})
As I mentioned before, I need to return objects based on that data in the format of:
var item = {name:"",price:0}
However, things like price will always be changing.
Based on the data thats in the div, the final product would look along the lines of :
var x = {name:"a",price:1}
var x2 = {name:"a2",price:2}
How do I go about doing this? I thought maybe i could store the data in an array, and then do something like
for(x in y){
return object
}
or something along those lines.
Sorry if this seems like a bonehead question, I'm pretty new to javascript.
clarification: i'm trying to figure out how to return multiple objects based on the data inside the div.

Here is the code that builds an array of objects based on two arrays (assuming they are of equal length).
function buildStocks() {
// Names and prices can also be passed as function arguments
var names = ['a', 'b', 'c'];
var prices = [1, 2, 3];
var result = []; // Array of these objects
for (var i = 0; i < names.length; i++) {
result.push({
name: names[i],
price: prices[i]
});
}
return result;
}

Numerically ordered ID's of data objects in Firebase

I am pretty new to the 'game' and was wondering if it's possible to order newly added data (through a form and inputs) to the Firebase numerically so each new data entry gets the ID (number of the last added data +1).
To make it more clear, underneath you can find a screenshot of how data is currently being added right now. The datapoint 0-7 are existing (JSON imported data) and the ones with the randomly created ID belong to new entries. I would like to have the entries to comply to the numbering inside of my Firebase, because otherwise my D3 bar chart won't be visualised.
var firebaseData = new Firebase("https://assignment5.firebaseio.com");
function funct1(evt)
{
var gameName = $('#nameInput').val();
var medalCount = $('#medalsInput').val();
var bool = $('#boolInput').is(':checked');
firebaseData.push().set({games: gameName, medals: medalCount, summergames: bool});
evt.preventDefault();
}
var submit = document.getElementsByTagName('button')[0];
submit.onclick = funct1;
UPDATE:
function funct1(evt)
{
var gameName = $('#nameInput').val();
var medalCount = $('#medalsInput').val();
var bool = $('#boolInput').is(':checked');
for (var i = 0; i < 10; i++)
{
firebaseData.child('7' + i).set({games: gameName, medals: medalCount, summergames: bool}(i)); };
Problem:

There are two ways to generate ids for your document nodes.
Calling .push() on your reference will generate that unique id.
Calling .set() on your reference will allow you to use your own
id.
Right now you're using .push().set({}), so push will generate an new id and the set will simply set the data.
// These two methods are equivalent
listRef.push().set({user_id: 'wilma', text: 'Hello'});
listRef.push({user_id: 'wilma', text: 'Hello'});
Using .set() without .push() will allow you to control your own id.
Using .push():
When managing lists of data in Firebase, it's important to use unique generated IDs since the data is updating in real time. If integer ids are being used data can be easily overwritten.
Just because you have an unique id, doesn't mean you can't query through your data by your ids. You can loop through a parent reference and get all of the child references as well.
var listRef = new Firebase('https://YOUR-FIREBASE.firebaseio.com/items');
// constructor for item
function Item(id) {
this.id = id;
};
// add the items to firebase
for (var i = 0; i < 10; i++) {
listRef.push(new Item(i));
};
// This will generate the following structure
// - items
// - LGAJlkejagae
// - id: 0
// now we can loop through all of the items
listRef.once('value', function (snapshot) {
snapshot.forEach(function (childSnapshot) {
var name = childSnapshot.name();
var childData = childSnapshot.val();
console.log(name); // unique id
console.log(childData); // actual data
console.log(childData.id); // this is the id you're looking for
});
});
Within the childData variable you can access your data such as the id you want.
Using .set()
If you want to manage your own ids you can use set, but you need to change the child reference as you add items.
for (var i = 0; i < 10; i++) {
// Now this will create an item with the id number
// ex: https://YOUR-FIREBASE.firebaseio.com/items/1
listRef.child('/' + i).set(new Item(i));
};
// The above loop with create the following structure.
// - items
// - 0
// - id: 0
To get the data you can use the same method above to loop through all of the child items in the node.
So which one to use?
Use .push() when you don't want your data to be easily overwritten.
Use .set() when your id is really, really important to you and you don't care about your data being easily overwritten.
EDIT
The problem you're having is that you need to know the total amount of items in the list. This feature is not implemented in Firebase so you'll need to load the data and grab the number of items. I'd recommend doing this when the page loads and caching that count if you really desire to maintain that id structure. This will cause performance issues.
However, if you know what you need to index off of, or don't care to overwrite your index I wouldn't load the data from firebase.
In your case your code would look something like this:
// this variable will store all your data, try to not put it in global scope
var firebaseData = new Firebase('your-firebase-url/data');
var allData = null;
// if you don't need to load the data then just use this variable to increment
var allDataCount = 0;
// be wary since this is an async call, it may not be available for your
// function below. Look into using a deferred instead.
firebaseData.once('value', function(snapshot) {
allData = snapshot.val();
allDataCount = snapshot.numChildren(); // this is the index to increment off of
});
// assuming this is some click event that adds the data it should
function funct1(evt) {
var gameName = $('#nameInput').val();
var medalCount = $('#medalsInput').val();
var bool = $('#boolInput').is(':checked');
firebaseData.child('/' + allDataCount).set({
games: gameName,
medals: medalCount,
summergames: bool
});
allDataCount += 1; // increment since we still don't have the reference
};
For more information about managing lists in Firebase, there's a good article in the Firebase API Docs. https://www.firebase.com/docs/managing-lists.html

AngularJS Convert Array to JSON

I have an array containing 3 elements
var a = [];
a["username"]=$scope.username;
a["phoneNo"]=$scope.phoneNo;
a["altPhoneNo"]=$scope.altPhoneNo;
Now, I want to send this data to server in JSON format. Therefore, I used
var aa = JSON.stringify(a);
console.log("aa = "+aa);
But the console displays empty array
aa = []
How can I convert this array into JSON?

That's not the correct way to add elements to an array, you're adding properties instead.
If you did console.log(a.username); you'd see your $scope.username value.
You could either do
var a = [];
a.push({"username": $scope.username});
a.push({"phoneNo": $scope.phoneNo});
a.push({"altPhoneNo": $scope.altPhoneNo});
But it looks more like what you're trying to do is
var a = {};
a["username"] = $scope.username;
a["phoneNo"] = $scope.phoneNo;
a["altPhoneNo"] = $scope.altPhoneNo;
That is, you want your a to be an object if you're going to add properties to it.
And that would be better written as
var a = {};
a.username = $scope.username;
a.phoneNo = $scope.phoneNo;
a.altPhoneNo = $scope.altPhoneNo;

access javascript array element by JSON object key

I have an array that looks like this
var Zips = [{Zip: 92880, Count:1}, {Zip:91710, Count:3}, {Zip:92672, Count:0}]
I would like to be able to access the Count property of a particular object via the Zip property so that I can increment the count when I get another zip that matches. I was hoping something like this but it's not quite right (This would be in a loop)
Zips[rows[i].Zipcode].Count
I know that's not right and am hoping that there is a solution without looping through the result set every time?
Thanks

I know that's not right and am hoping that there is a solution without
looping through the result set every time?
No, you're gonna have to loop and find the appropriate value which meets your criteria. Alternatively you could use the filter method:
var filteredZips = Zips.filter(function(element) {
return element.Zip == 92880;
});
if (filteredZips.length > 0) {
// we have found a corresponding element
var count = filteredZips[0].count;
}
If you had designed your object in a different manner:
var zips = {"92880": 1, "91710": 3, "92672": 0 };
then you could have directly accessed the Count:
var count = zips["92880"];

In the current form, you can not access an element by its ZIP-code without a loop.
You could transform your array to an object of this form:
var Zips = { 92880: 1, 91710: 3 }; // etc.
Then you can access it by
Zips[rows[i].Zipcode]
To transform from array to object you could use this
var ZipsObj = {};
for( var i=Zips.length; i--; ) {
ZipsObj[ Zips[i].Zip ] = Zips[i].Count;
}

Couple of mistakes in your code.
Your array is collection of objects
You can access objects with their property name and not property value i.e Zips[0]['Zip'] is correct, or by object notation Zips[0].Zip.
If you want to find the value you have to loop

If you want to keep the format of the array Zips and its elements
var Zips = [{Zip: 92880, Count:1}, {Zip:91710, Count:3}, {Zip:92672, Count:0}];
var MappedZips = {}; // first of all build hash by Zip
for (var i = 0; i < Zips.length; i++) {
MappedZips[Zips[i].Zip] = Zips[i];
}
MappedZips is {"92880": {Zip: 92880, Count:1}, "91710": {Zip:91710, Count:3}, "92672": {Zip:92672, Count:0}}
// then you can get Count by O(1)
alert(MappedZips[92880].Count);
// or can change data by O(1)
MappedZips[92880].Count++;
alert(MappedZips[92880].Count);
jsFiddle example

function getZip(zips, zipNumber) {
var answer = null;
zips.forEach(function(zip){
if (zip.Zip === zipNumber) answer = zip;
});
return answer;
}
This function returns the zip object with the Zip property equal to zipNumber, or null if none exists.

did you try this?
Zips[i].Zip.Count