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How to get specific data from object array?

I'm a beginner and would like to know how I can get a specific object from an array
I have an Array that looks like this:
data {
"orderid": 5,
"orderdate": "testurl.com",
"username": "chris",
"email": "",
"userinfo": [
{
"status": "processing",
"duedate": "" ,
}
]
},
To get the data from above I would do something like this:
return this.data.orderid
But how can I go deeper and get the status in userinfo?
return this.data.orderid.userinfo.status
doesn't work... anyone have any ideas?

A few points:
data is not an array, is an Object (see the curly braces, arrays have squared brackets). To be really precise, your syntax is invalid, but I assume you wanted to type data = { ... }, as opposed to data { ... }
Your syntax is almost correct, the only mistake you are making is that userinfo is an array, and arrays have numeric indexes (I.e. array[0], array[1]). What you are looking for is this.data.orderid.userinfo[0].status

Use data.userinfo[0].status to get the value (in your case this.data.userinfo[0].status)
var data = {
"orderid": 5,
"orderdate": "testurl.com",
"username": "chris",
"email": "",
"userinfo": [
{
"status": "processing",
"duedate": "" ,
}
]
};
console.log(data.userinfo[0].status);

User Info is an array, so you would need to access it using indexer like so:
return this.data.userinfo[0].status
MDN on arrays: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array

You need to iterate over data.userinfo (it's an array)
var data = {
"orderid": 5,
"orderdate": "testurl.com",
"username": "chris",
"email": "",
"userinfo": [
{
"status": "processing",
"duedate": "" ,
}
]
};
data.userinfo.forEach(function(element) {
console.log(element.status);
});

Search in json file with Node JS

I have several objects like this and wonder how I can search between these, say that we got the number 1 and want to figure out what the name is.
Should I loop it or what do you guys suggest?
To make things clear, I do want to get the other objects by using the number. Is it possible?
{
"room": [
{
"number": "1",
"name": "room1"
},
{
"number": "2",
"name": "room2"
}
]
}

You could use a map and use the room number as identifier. This way you can access the room data via the room number like that:
var data = {
"room": [
{
"number": "1",
"name": "room1"
},
{
"number": "2",
"name": "room2"
}
]
};
// or load it from a file:
// var data = require('./data.json');
var rooms = new Map();
for(room of data.room) {
rooms.set(Number(room.number), room);
}
// access data for room with number 1
alert(rooms.get(1).name);

Firstly, bring in the file. Make sure to include the './' before the file name to show that it's from the current directory.
const data = require('./data.json');
Now the JSON data is stored inside the variable data. To access the members, use the dot operator. data.room will return the array of rooms.
To access the individual room, use data.room[i] where i is the numbered element in the array (starting from 0). For example, to access the first room:
const first_room = data.room[0];
This first_room variable can now be used to access the name.
console.log(first_room.name);
This will log "room1" to the console.

You can try this. This will help you.
var roomData = {
"room": [
{
"number": "1",
"name": "room1"
},
{
"number": "2",
"name": "room2"
}
]
}
for(key in roomData.room){
console.log("Room Number - " + roomData.room[key].number);
console.log("Room Name - " + roomData.room[key].name);
}

Javascript create an object, keyed by array value

I have a method which needs to return a user object from a supplied id parameter. Further methods will use this structure so it's not a simple case of using the existing structure.
Essentially I have a database which contains a type key, this is filtered so that I have a collection of users. What I need to do is create an object which is keyed by the users _id value and contains the users object with the _id and type omitted.
Using lodash or some ES6 sugar I would like to transform the following Array;
[
{
"_id": "0e12e661cb50068a135b36067f001d20",
"name": "Joe Bloggs",
"type": "user"
},
{
"_id": "0e12e661cb50068a135b36067f00373f",
"name": "Ben Bloggs",
"type": "user"
}
]
Into the following Object, with the _id and type omitted;
{
"0e12e661cb50068a135b36067f001d20": {
"name": "Joe Bloggs"
},
"0e12e661cb50068a135b36067f00373f": {
"name": "Ben Bloggs"
}
}
EDIT I need to return the object and NOT the name as further properties could be added to these objects.

You can do this with just reduce().
var data = [{
"_id": "0e12e661cb50068a135b36067f001d20",
"name": "Joe Bloggs",
"type": "user"
}, {
"_id": "0e12e661cb50068a135b36067f00373f",
"name": "Ben Bloggs",
"type": "user"
}]
var result = data.reduce(function(r, e) {
r[e._id] = {name: e.name};
return r;
}, {})
console.log(result)
ES6 version with arrow function
var result = data.reduce((r, e) => (r[e._id] = {name: e.name}, r), {})
Update: To just exclude specific properties from new object you can use Object.assign() DEMO to create copy of object and then delete to delete some properties or you can use forEach() loop and add properties that you want DEMO

Add data to end of ko.observablearray

I'm trying to add data to the end of an observable array but it's just not working as expected. I bet it is something minor but I just can't get my head around it.
What I am doing:
self.businesses = ko.observableArray();
function Business(business) {
var self = this;
self.BusinessID = ko.observable(business.BusinessID );
self.Type = ko.observable(business.Type);
self.Location = ko.observable(business.Location);
}
/*ajax get array of businesses as follows:
[
{
"$id": "1",
"BusinessID ": 62,
"Type": "Data",
"Location": "Data"
},
{
"$id": "2",
"BusinessID ": 63,
"Type": "Data",
"Location": "Data"
},
{
"$id": "3",
"BusinessID ": 64,
"Type": "Data",
"Location": "Data",
} ]
*/
var mappedBusinesses = $.map(data, function (business) { return new Business(business) });
self.businesses(mappedBusinesses);
This all works as expected and the obersablearray is populated.
However if I go to add another business, it wont work. For example, if I call the ajax that returns this (as newBusiness):
{
"$id": "1",
"BusinessID ": 68,
"Type": "Data",
"Location": "Data"
}
and I do:
self.businesses().push(newBusiness);
It adds to the array as an "Object" not a Business. So I thought I would do:
var bus = $.map(newBusiness, function (business) { return new Business(business) });
self.businesses().push(bus);
But I get the error in the JS console "Uncaught TypeError: Cannot read property 'BusinessID' of null
So I made a new var and added the brackets: [] in and it adds to the observable array but not as a "Business" object but rather as an "Array[1]" object at the end and this doesn't function as per the others. Code as follows:
var newBus = {
BusinessID: newBusiness.BusinessID,
Type: newBusiness.Type,
Location: newBusiness.Location
}
var bus = $.map(newBus, function (business) { return new Business(business) });
self.businesses().push(bus);
As mentioned this adds to the observable array but doesn't actually add as a "business" object but rather as an "array[1]" object.
I bet it's something so basic but just can't get it working!

Argh I knew it would be simple!
It was posting the whole array to the ObservableArray...not just the object.
The fix:
self.businesses.push(newBusiness[0])
Had to add the [0] in to get it to push the actual data into the array, not the object!
Thanks for the answers!

You're evaluating the array with your push:
self.businesses().push(newBusiness);
Observable Arrays have their own array functions, you should just do this (no parens):
self.businesses.push(newBusiness);
See this page: http://knockoutjs.com/documentation/observableArrays.html

Delete object from json tree by reference in JavaScript

I need to remove an object from an JSON tree. I know a reference to that object. Is there a nice way to do it via JavaScript or jQuery besides traversing the whole tree?
Example:
party = {
"uuid": "4D326531-3C67-4CD2-95F4-D1708CE6C7A8",
"link": {
"rel": "self",
"href": "http://localhost:8080/cim/party/4D326531-3C67-4CD2-95F4-D1708CE6C7A8"
},
"type": "PERSON",
"name": "John Doe",
"properties": {
"CONTACT": [
{
"category": "CONTACT",
"type": "EMAIL",
"key": "email",
"value": "john.doe#doe.at",
"id": "27DDFF6E-5235-46BF-A349-67BEC92D6DAD"
},
{
"category": "CONTACT",
"type": "PHONE",
"key": "mobile",
"value": "+43 999 999990 3999",
"id": "6FDAA4C6-9340-4F11-9118-F0BC514B0D77"
}
],
"CLIENT_DATA": [
{
"category": "CLIENT_DATA",
"type": "TYPE",
"key": "client_type",
"value": "private",
"id": "65697515-43A0-4D80-AE90-F13F347A6E68"
}
]
},
"links": []
}
And i have a reference: contact = party.properties.contact[1]. And I want to do something like delete contact.

You may delete it this way. I just tested it.
var party = {
// ...
}
alert(party.properties.CONTACT[0]) // object Object
delete party.properties.CONTACT[0] // true
alert(party.properties.CONTACT[0]) // undefined
Fiddle
UPDATE
In the case above party is a direct property of window object
window.hasOwnProperty('party'); // true
and that's why you can't delete a property by reference. Anyhow, behavior of delete operator with host objects is unpredictable. Though, you may create a scope around the party object and then you'll be allowed to delete it.
var _scope = {};
var _scope.party = {
// ...
};
var r = _scope.party.properties.CONTACT[0];
window.hasOwnProperty('party'); // false
alert(r) // object Object
delete r // true
alert(r) // undefined

It only works one way: a variable holds a reference, but there is no way given a particular reference to infer what variables hold it (without iterating over them and comparing).