Reading JSON data for a particular ID - javascript

I have some JSON data which is in the following format:
[
{
"id": 145,
"Name": "John",
"company_name": "A",
"email": "john#gmail.com",
"country": "USA"
},
{
"id": 500,
"Name": "Mike",
"company_name": "B",
"email": "mike#gmail.com",
"country": "London"
},
{
"id": 100,
"Name": "Sally",
"company_name": "C",
"email": "sally#gmail.com",
"country": "USA"
}
]
Now, suppose I ask the user to enter an id, say 100. Then I need to display all the details for this id.
I am supposed to do this as a part of a web application,where I have to invoke an display the fields of a particular id. This would have been easy if I had a hash like implementation and could display all parameters based on the key-id.
Can anybody tell me how this can be done using such kind of data?
Thanks!

You could use something like this:
(Assuming the you have a variable data with your Json Object).
function getid(id) {
var nobj;
data.forEach(function(obj) {
if(obj.id == id)
nobj = obj;
});
return nobj
}
var neededobj = getid(100);
console.log(neededobj.Name + "\n" + neededobj.email + "\netc...");
But to get the Object you have to loop through your complete array,
until it finds the right Object
see this Fiddle

I think you are looking for Associative Array,
the simplex one would be,
var associativeArray = [];
associativeArray["one"] = "First";
associativeArray["two"] = "Second";
associativeArray["three"] = "Third";
alert(associativeArray.one);
And obviusly you can add json object in value place

Related

Delete an object in Scope

This question might not even be related to angularjs and the solution could be plain old js or jquery. But that is what i what to find out.
I want to implement a delete functionality for a particular user and i am wondering if there is a easier way to do this in angularjs or should it be plain old JS?
i have a fairly complex object for eg (going up to 4 levels):
{
"Department": [
{
"Name": "Accounting",
"users": [
{
"id": "1",
"firstName": "John",
"lastName": "Doe",
"age": 23
},
{
"id": "2",
"firstName": "Mary",
"lastName": "Smith",
"age": 32
}
]
},
{
"Name": "Sales",
"users": [
{
"id": "3",
"firstName": "Sally",
"lastName": "Green",
"age": 27
},
{
"id": "4",
"firstName": "Jim",
"lastName": "Galley",
"age": 41
}
]
}
]
}
this is displayed in a ng-repeat where we should Department and username. If I want to delete a particular user i make an api call and on success of it, I want to delete that object. so i have a js method like this
function DeleteUser(user) {
$.each(ctrl.UserData, function(index, value) {
var filteredPeople = value.filter((item) => item.id !== user.id);
});
The question I have is, if i want to delete this object is there any easier way to delete from model since i have the object here or i have to do the classic jquery way of using like $.grep or filter to iterate through each object and match by id and then delete it?
Presumably, you're iterating over the departments (accounting, sales) in your template, and then over the users in that department.
So you could have, in your template:
<button ng-click="deleteUser(user, department)">...</button>
And the method could thus be as simple as
$scope.deleteUser = function(user, department) {
// delete user from backend, then
department.users.splice(departments.users.indexOf(user), 1);
}
If you really don't want to pass the department, then loop over the departments, and use the above if departments.users.indexOf(user) returns a value that is >= 0.

How to get specific array from JSON object with Javascript?

I am working with facebook JS SDK which returns user's information in JSON format. I know how to get the response like response.email which returns email address. But how to get an element from a nested array object? Example: user's education history may contain multiple arrays and each array will have an element such as "name" of "school". I want to get the element from the last array of an object.
This is a sample JSON I got:-
"education": [
{
"school": {
"id": "162285817180560",
"name": "Jhenaidah** School"
},
"type": "H**hool",
"year": {
"id": "14404**5610606",
"name": "2011"
},
"id": "855**14449421"
},
{
"concentration": [
{
"id": "15158**968",
"name": "Sof**ering"
},
{
"id": "20179020**7859",
"name": "Dig**ty"
}
],
"school": {
"id": "10827**27428",
"name": "Univer**g"
},
"type": "College",
"id": "9885**826013"
},
{
"concentration": [
{
"id": "108196**810",
"name": "Science"
}
],
"school": {
"id": "2772**996993",
"name": "some COLLEGE NAME I WANT TO GET"
},
"type": "College",
"year": {
"id": "1388*****",
"name": "2013"
},
"id": "8811215**16"
}]
Let's say I want to get "name": "some COLLEGE NAME I WANT TO GET" from the last array. How to do that with Javascript? I hope I could explain my problem. Thank you
Here is a JsFiddle Example
var json = '{}' // your data;
// convert to javascript object:
var obj = JSON.parse(json);
// get last item in array:
var last = obj.education[obj.education.length - 1].school.name;
// result: some COLLEGE NAME I WANT TO GET
If your json above was saved to an object called json, you could access the school name "some COLLEGE NAME I WANT TO GET" with the following:
json.education[2].school.name
If you know where that element is, then you can just select it as already mentioned by calling
var obj = FACEBOOK_ACTION;
obj.education[2].school.name
If you want to select specifically the last element, then use something like this:
obj.education[ obj.education.length - 1 ].scool.name
Try this,
if (myData.hasOwnProperty('merchant_id')) {
// do something here
}
where JSON myData is:
{
amount: "10.00",
email: "someone#example.com",
merchant_id: "123",
mobile_no: "9874563210",
order_id: "123456",
passkey: "1234"
}
This is a simple example for your understanding. In your scenario of nested objects, loop over your JSON data and use hasOwnProperty to check if key name exists.

get string of elements by name

I'm newbee in JS so i need your help.
I have this JSON code :
{
"data": {
"people": [
"get_my_obj": [
{
"yearcome": 2006,
"email": "email1#test.com",
"came": "1.12",
"name": "Alex "
},
{
"yearcome": 2010,
"email": "email2#test.com",
"came": "1.12",
"name": "John"
},
{
"yearcome": 2012,
"email": "email3#test.com",
"came": "1.12",
"name": "Max"
}
]
}
}
How i can get string of elements with emails?
For example var a = email1#test.com;email2#test.com;email3#test.com;
Thats really hard for me because if i have only 2 objects so string must show 2 emails if 3 objects show 3 emails.
Please help me find the way how to do it
var s = { data: ....};
var mails = s.data.people.get_my_obj.map(function (e) { return e.email; }).join(';');
console.log(mails);
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map

Printing JSON properties

I am currently trying to send a user information about a JSON object that I've recieved from an API. An example of the format is
[
{
"lang_code": "eng",
"site_language": "1",
"name": "English"
},
{
"lang_code": "afr",
"site_language": "1",
"name": "Afrikaans"
},
{
"lang_code": "ale",
"site_language": "0",
"name": "Aleut"
},
]
I want to be able to access the lang_code property of every single language and send it. I've tried to use
var languageCodes;
var languageResult = body.lang_code; //body is the result from a request.get({ ... })
for(var codes in languageResult) {
languageCodes = languageResult[codes];
}
Object.keys does nothing, as it just sends 72 numbers to me. Any thoughts?
On a side note, I also want people to be able to type "! languages [my command] eng", for example, and it sends "English" instead of just sending "1 is [object Object]".
Assuming body is the array at the top of your question, if you just want an array of all the language codes, this should suffice
var languageCodes = body.map(function(lang) {
return lang.lang_code;
});
var body = [{
"lang_code": "eng",
"site_language": "1",
"name": "English"
}, {
"lang_code": "afr",
"site_language": "1",
"name": "Afrikaans"
}, {
"lang_code": "ale",
"site_language": "0",
"name": "Aleut"
}];
var languageCodes = body.map(function(lang) {
return lang.lang_code;
});
document.getElementById('out').innerHTML = JSON.stringify(languageCodes);
<pre id="out"></pre>
I looped through your lang_codes like this:
var codes = [{"lang_code":"eng","site_language":"1","name":"English"}, {"lang_code":"afr","site_language":"1","name":"Afrikaans"},{"lang_code":"ale","site_language":"0","name":"Aleut"}];
for(var i = 0; i < codes.length; i++) {
console.log(codes[i].lang_code);
}

Javascript - searching object by key

I know there's plenty of answers on this and most are suggesting looping thru the object, returning what you need, I'm not sure this is the best approach, in my case anyway.
What I have is array with entries referencing to another array people(with id and name) by person_id and projects(with id and name) by project_id.
What I need is to be able to access project and person with a particular id inside the loop on entries, so I can get their names. Doing what others have suggested I'd loop thru people and projects inside each irritation of entries, which seems like awful lot of looping.
So I thought I'd make something I called a "hashtable" from both people and projects on init, which means pretty much creating a new objects people_hashtable and projects_hashtable where key would be the id
so
[
{
"id": "8",
"name": "John Doe"
}
]
would became
{
"8": {
"name": "John Doe"
}
}
this way I'd have easy access to the name without looping all the time while still maintaining the old array with its original order(that's why I'm not outputting it this way directly from server, you can't quite order an object and I'm using both people and projects in a selectbox, which needs to be ordered by name).
Am I doing it right? Are there better way? Or should I forget this completely and stick with the search loop as suggested in other question?
I'm trying to be as efficient as possible on both server and client side.
You basically doubled all the objects just to avoid loop. So, unless you have some bad performance issues, I would avoid that.
In case you really, really need a kind of hashmap, I would prefer storing the array's index instead of another copy of the object:
// array
var arr = [
{
"id": "8",
"name": "John Doe"
}
];
// lookup table
var lookup = {
"8": 0
}
Of course doing that, means you can't modifying the array's without rebuild the hashmap.
Generate it's quite simple:
var lookup = arr.reduce(function(lookup, item, index) {
lookup[item.id] = index;
return lookup;
}, {});
You can also use that to generate the object you mentioned your question:
var lookup = arr.reduce(function(lookup, item) {
lookup[item.id] = {name: item.name};
return lookup;
}, {});
But as I said it's something I would avoid.
Following code may help you. JSFIDDLE
var arr = [
{
"id": "8",
"name": "John Doe"
}
];
var obj = {};
for(var i=0; i< arr.length; i++){
obj[arr[i].id] = {name: arr[i].name};
}
console.log(obj);
var articles= {
"item1":{
"id":"155",
"name":"First Item",
"value":-5199.6
},
"item2":{
"id":"255",
"name":"Second Item",
"value":-424.91
}
}
var ids = [];
for(var item in articles) {
ids.push(articles[item]['id']);
}
console.log(ids);
This lib https://github.com/paularmstrong/normalizr makes it pretty easy to do. Both normalization and denormalization.
It can turn this
{
"id": "123",
"author": {
"id": "1",
"name": "Paul"
},
"title": "My awesome blog post",
"comments": [
{
"id": "324",
"commenter": {
"id": "2",
"name": "Nicole"
}
}
]
}
into this
{
result: "123",
entities: {
"articles": {
"123": {
id: "123",
author: "1",
title: "My awesome blog post",
comments: [ "324" ]
}
},
"users": {
"1": { "id": "1", "name": "Paul" },
"2": { "id": "2", "name": "Nicole" }
},
"comments": {
"324": { id: "324", "commenter": "2" }
}
}
}
and the other way around.

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