I have the following code in an array for Javascript JSON:
params = {
"fighters": [
{
"name": "Muhammad Ali",
"nickname": "The Greatest"
},
{
"name": "Chuck Liddell",
"nickname": "The Iceman"
}
]
};
Now I have "N" variable data "name" and "nickname" from a database SQLITE.
The idea is to show all the "nick" and "nickname" that exist from the database iteratively.
How I can fill it?
I tested with a FOR that runs all the arrangements and I charge them, for it did something like this:
params = {
"fighters": [ show[i] ]
};
It does not work.
I hope I explained correctly.
Thanks.
That will retrieve all fighters names:
var len = params.fighters.length;
for (var i = 0; i < len; i++) {
console.log( params.fighters[i].name );
}
To change fighters names values do the following:
var len = params.fighters.length;
for (var i = 0; i < len; i++) {
params.fighters[i].name = 'Your_Fighter_Name';
}
Hopefully i have helped you.
assuming we're in the fetchAll(function (error, rows) {}) callback using node-sqlite (meaning rows is an array of objects, with the keys in the objects being the column names):
var params = { "fighters" : [] };
rows.forEach(function (row) {
params.fighters.push({name: row.name, nickname: row.nickname});
});
Remember, JSON is subset of JS, it is not it's own language. It's NOT a programming language. You can't "do" anything in JSON, as it is not a programming language. You can't iterate, recurse, fill... you can do that with JS.
Sorry for repeating myself, but apparently a lot of people mistake JSON for something it isn't. I'm not assuming you do, but it can't be said too often ;-) How you want to send the JSON I can't tell you, as there is no information in your question. If you want to do this via a byte-based protocol such as HTTP you might want to use JSON.stringify() to get a textual representation of your object that you can send over the network.
See my version of your fiddle: http://jsfiddle.net/dpL4c/2/ .
Related
I'm parsing an order feed to identify duplicate items bought and group them with a quantity for upload. However, when I try to map the resulting array, it's showing [object Object], which makes me think something's converting the return into an object rather than an array.
The function is as follows:
function compressedOrder (original) {
var compressed = [];
// make a copy of the input array
// first loop goes over every element
for (var i = 0; i < original.length; i++) {
var myCount = 1;
var a = new Object();
// loop over every element in the copy and see if it's the same
for (var w = i+1; w < original.length; w++) {
if (original[w] && original[i]) {
if (original[i].sku == original[w].sku) {
// increase amount of times duplicate is found
myCount++;
delete original[w];
}
}
}
if (original[i]) {
a.sku = original[i].sku;
a.price = original[i].price;
a.qtty = myCount;
compressed.push(a);
}
}
return compressed;
}
And the JS code calling that function is:
contents: compressedOrder(item.lineItems).map(indiv => ({
"id": indiv.sku,
"price": indiv.price,
"quantity": indiv.qtty
}))
The result is:
contents: [ [Object], [Object], [Object], [Object] ]
When I JSON.stringify() the output, I can see that it's pulling the correct info from the function, but I can't figure out how to get the calling function to pull it as an array that can then be mapped rather than as an object.
The correct output, which sits within a much larger feed that gets uploaded, should look like this:
contents:
[{"id":"sku1","price":17.50,"quantity":2},{"id":"sku2","price":27.30,"quantity":3}]
{It's probably something dead simple and obvious, but I've been breaking my head over this (much larger) programme till 4am this morning, so my head's probably not in the right place}
Turns out the code was correct all along, but I was running into a limitation of the console itself. I was able to verify this by simply working with the hard-coded values, and then querying the nested array separately.
Thanks anyway for your help and input everyone.
contents: compressedOrder(item.lineItems).map(indiv => ({
"id": indiv.sku,
"price": indiv.price,
"quantity": indiv.qtty
}))
In the code above the compressedOrder fucntion returns an array of objects where each object has sku, price and qtty attribute.
Further you are using a map on this array and returning an object again which has attributes id, price and quantity.
What do you expect from this.
Not sure what exactly solution you need but I've read your question and the comments, It looks like you need array of arrays as response.
So If I've understood your requirement correctly and you could use lodash then following piece of code might help you:
const _ = require('lodash');
const resp = [{key1:"value1"}, {key2:"value2"}].map(t => _.pairs(t));
console.log(resp);
P.S. It is assumed that compressedOrder response looks like array of objects.
Introduction
I'm learning JavaScript on my own and JSON its something along the path. I'm working on a JavaScript WebScraper and I want, for now, load my results in JSON format.
I know I can use data base, server-client stuff, etc to work with data. But I want to take this approach as learning JSON and how to parse/create/format it's my main goal for today.
Explaining variables
As you may have guessed the data stored in the fore mentioned variables comes from an html file. So an example of the content in:
users[] -> "Egypt"
GDP[] -> "<td> $2,971</td>"
Regions[] -> "<td> Egypt </td>"
Align[] -> "<td> Eastern Bloc </td>"
Code
let countries = [];
for(let i = 0; i < users.length; i++)
{
countries.push( {
'country' : [{
'name' : users[i],
'GDP' : GDP[i],
'Region' : regions[i],
'Align' : align[i]
}]})
};
let obj_data = JSON.stringify(countries, null, 2);
fs.writeFileSync('countryballs.json', obj_data);
Code explanation
I have previously loaded into arrays (users, GDP, regionsm align) those store the data (String format) I had extracted from a website.
My idea was to then "dump" it into an object with which the stringify() function format would format it into JSON.
I have tested it without the loop (static data just for testing) and it works.
Type of error
let obj_data = JSON.stringify(countries, null, 2);
^
TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Node'
| property 'children' -> object with constructor 'Array'
| index 0 -> object with constructor 'Node'
--- property 'parent' closes the circle
What I want from this question
I want to know what makes this JSON format "Circular" and how to make this code work for my goals.
Notes
I am working with Node.js and Visual Studio Code
EDIT
This is further explanation for those who were interested and thought it was not a good question.
Test code that works
let countries;
console.log(users.length)
for(let i = 0; i < users.length; i++)
{
countries = {
country : [
{
"name" : 'CountryTest'
}
]
}
};
let obj_data = JSON.stringify(countries, null, 2);
fs.writeFileSync('countryballs.json', obj_data);
});
Notice in comparison to the previous code, right now I am inputing "manually" the name of the country object.
This way absolutely works as you can see below:
Now, if I change 'CountryTest' to into a users[i] where I store country names (Forget about why countries are tagged users, it is out of the scope of this question)
It shows me the previous circular error.
A "Partial Solution" for this was to add +"" which, as I said, partially solved the problem as now there is not "Circular Error"
Example:
for(let i = 0; i < users.length; i++)
{
countries = {
country : [
{
"name" : users[i]+''
}
]
}
};
Resulting in:
Another bug, which I do not know why is that only shows 1 country when there are 32 in the array users[]
This makes me think that the answers provided are not correct so far.
Desired JSON format
{
"countries": {
"country": [
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
},
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
},
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
}
]}
}
Circular structure error occurs when you have a property of the object which is the object itself directly (a -> a) or indirectly (a -> b -> a).
To avoid the error message, tell JSON.stringify what to do when it encounters a circular reference. For example, if you have a person pointing to another person ("parent"), which may (or may not) point to the original person, do the following:
JSON.stringify( that.person, function( key, value) {
if( key == 'parent') { return value.id;}
else {return value;}
})
The second parameter to stringify is a filter function. Here it simply converts the referred object to its ID, but you are free to do whatever you like to break the circular reference.
You can test the above code with the following:
function Person( params) {
this.id = params['id'];
this.name = params['name'];
this.father = null;
this.fingers = [];
// etc.
}
var me = new Person({ id: 1, name: 'Luke'});
var him = new Person( { id:2, name: 'Darth Vader'});
me.father = him;
JSON.stringify(me); // so far so good
him.father = me; // time travel assumed :-)
JSON.stringify(me); // "TypeError: Converting circular structure to JSON"
// But this should do the job:
JSON.stringify(me, function( key, value) {
if(key == 'father') {
return value.id;
} else {
return value;
};
})
The answer is from StackOverflow question,
Stringify (convert to JSON) a JavaScript object with circular reference
From your output, it looks as though users is a list of DOM nodes. Rather than referring to these directly (where there are all sort of possible cyclical structures), if you just want their text, instead of using users directly, try something like
country : [
{
"name" : users[i].textContent // maybe also followed by `.trim()
}
]
Or you could do this up front to your whole list:
const usersText = [...users].map(node => node.textContent)
and then use usersText in place of users as you build your object.
If GDP, regions and align are also references to your HTML, then you might have to do the same with them.
EUREKA!
As some of you have mentioned above, let me tell you it is not a problem of circularity, at first..., in the JSON design. It is an error of the data itself.
When I scraped the data it came in html format i.e <td>whatever</td>, I did not care about that as I could simply take it away later. I was way too focused in having the JSON well formatted and learning.
As #VLAZ and #Scott Sauyezt mentioned above, it could be that some of the data, if it is not well formatted into string, it might be referring to itself somehow as so I started to work on that.
Lets have a look at this assumption...
To extract the data I used the cheerio.js which gives you a kind of jquery thing to parse html.
To extract the name of the country I used:
nullTest = ($('table').eq(2).find('tr').eq(i).find('td').find('a').last());
//"Partial solution" for the OutOfIndex nulls
if (nullTest != null)
{
users.push(nullTest);
}
(nullTest helps me avoid nulls, I will implement some RegEx when everything works to polish the code a bit)
This "query" would output me something like:
whatEverIsInHereIfThereIsAny
or else.
to get rid off this html thing just add .html() at the end of the "jquery" such as:
($('table').eq(2).find('tr').eq(i).find('td').find('a').last().html());
That way you are now working with String and avoiding any error and thus solves this question.
I have multiple records like this,
name: John Doe aliases: John, Doe, JD unique_id: 1 ...
My question is how do I search efficiently within the aliases & full name.
If the search query is any of those 4 (John Doe, John, Doe, JD) I would like to find the unique id (in this case 1).
What I have done: I have a very straightforward implementation that loops through the entire data until it finds. It takes a long time since the number of fields is very high.
Note: I am using javascript if it helps. Also I have the permission to change the data format (permanently), if it will make the search more efficient. Most of the search queries tend to be one of the aliases rather than full name.
Sample Code: https://jsfiddle.net/nh7yqafh/
function SearchJSON(json, query) {
var champs = json.champs;
for (var i = 0; i < champs.length; ++i) {
if (query == champs[i].name)
return champs[i].unique_id;
for (var j = 0; j < champs[i].aliases.length; ++j) {
if (query == champs[i].aliases[j])
return champs[i].unique_id;
}
}
}
//Data format is similar to what vivick said
var json_string = '{"count":5,"champs":[{"name":"Abomination","aliases":["abomination","AB","ABO"],"unique_id":1},{"name":"Black Bolt","aliases":["blackbolt","BB","BBT"],"unique_id":2},{"name":"Black Panther","aliases":["blackpanther","BP","BPR"],"unique_id":3},{"name":"Captain America","aliases":["captainamerica","CA","CAP"],"unique_id":4}]}'
var json = JSON.parse(json_string);
query="CA";
alert( "id of "+query+" is "+SearchJSON(json, query));
I guess you have a structure similar to the following one :
[
{
"name": "xxx",
"aliases": ["x", "xx", "xxx"],
"unique_id": 1,
/* [...] */
},
/* [...] */
]
You can then do something like this :
const queryParam = /*search query*/;
const arr = /* get the JSON record */;
const IDs = arr
.filter( entry =>(entry.aliases.includes(queryParam) || queryParam===entry.name) )
.map(entry=>entry.uniqueId);
This will give you an array of IDs which are potential matches.
If you need either 0 or 1 result only :
const ID = IDs[0] || null;
This will simply retrieve the first matched ID if there's one, otherwise it will set ID to null.
NB:
If you use an object of objects instead of an array of object, there's just a little bit of modifications to do (mainly using Object.entries) but it still is trivial.
PS:
I would recommend to always add the full name in the aliases, this will ease the filtering part (no || would be required).
UPDATE - Thanks for all the great answers and incredibly fast response. I've learned a great deal from the suggested solutions. I ultimately chose the answer I did because the outcome was exactly as I asked, and I was able to get it working in my application with minimal effort - including the search function. This site is an invaluable resource for developers.
Probably a simple task, but I can't seem to get this working nor find anything on Google. I am a Javascript novice and complex JSON confuses the hell out of me. What I am trying to do is make a PhoneGap Application (Phone Directory) for our company. I'll try to explain my reasoning and illustrate my attempts below.
I have JSON data of all of our employees in the following format:
[
{
"id":"1",
"firstname":"John",
"lastname":"Apple",
"jobtitle":"Engineer"
},
{
"id":"2",
"firstname":"Mark",
"lastname":"Banana",
"jobtitle":"Artist"
},
... and so on
]
The mobile framework (Framework 7) that I am using offers a "Virtual List" solution which I need to take advantage of as our directory is fairly large. The virtual list requires you to know the exact height of each list item, however, you can use a function to set a dynamic height.
What I am trying to do is create "headers" for the alphabetical listing based on their last name. The JSON data would have to be restructured as such:
[
{
"title":"A"
},
{
"id":"1",
"firstname":"John",
"lastname":"Apple",
"jobtitle":"Engineer"
},
{
"title":"B"
},
{
"id":"2",
"firstname":"Mark",
"lastname":"Banana",
"jobtitle":"Artist"
},
... and so on
]
I've been able to add key/value pairs to existing objects in the data using a for loop:
var letter, newLetter;
for(var i = 0; i < data.length; i++) {
newLetter = data[i].lastname.charAt(0);
if(letter != newLetter) {
letter = newLetter
data[i].title = letter;
}
}
This solution changes the JSON, thus outputting a title bar that is connected to the list item (the virtual list only accepts ONE <li></li> so the header bar is a div inside that bar):
{
"id":"1",
"firstname":"John",
"lastname":"Apple",
"jobtitle":"Engineer",
"title":"A"
},
{
"id":"1",
"firstname":"Mike",
"lastname":"Apricot",
"jobtitle":"Engineer",
"title":""
}
This solution worked until I tried implementing a search function to the listing. When I search, it works as expected but looks broken as the header titles ("A", "B", etc...) are connected to the list items that start the particular alphabetical section. For this reason, I need to be able to separate the titles from the existing elements and use them for the dynamic height / exclude from search results.
The question: How can I do a for loop that inserts [prepends] a NEW object (title:letter) at the start of a new letter grouping? If there is a better way, please enlighten me. As I mentioned, I am a JS novice and I'd love to become more efficient programming web applications.
var items = [
{ "lastname":"Apple" },
{ "lastname":"Banana" },
{ "lastname":"Box" },
{ "lastname":"Bump" },
{ "lastname":"Can" },
{ "lastname":"Switch" }
];
var lastC = null; //holds current title
var updated = []; //where the updated array will live
for( var i=0;i<items.length;i++) {
var val = items[i]; //get current item
var firstLetter = val.lastname.substr(0,1); //grab first letter
if (firstLetter!==lastC) { //if current title does not match first letter than add new title
updated.push({title:firstLetter}); //push title
lastC = firstLetter; //update heading
}
updated.push(val); //push current index
}
console.log(updated);
Well right now you have an array of objects - prefixing the title as its own object may be a bit confusing - a better structure may be:
[
{
title: "A",
contacts: [
{
"id":"1",
"firstname":"John",
"lastname":"Apple",
"jobtitle":"Engineer",
"title":"A"
}
]
Given your current structure, you could loop and push:
var nameIndexMap = {};
var newContactStructure = [];
for (var i = 0; i < data.length; i++) {
var letter = data[i].lastname.charAt(0);
if (nameIndexMap.hasOwnProperty(letter)) {
//push to existing
newContactStructure[nameIndexMap[letter]].contacts.push(data[i])
} else {
//Create new
nameIndexMap[letter] = newContactStructure.length;
newContactStructure.push({
title: letter,
contacts: [
data[i]
]
});
}
}
newContactStructure will now contain your sorted data.
Demo: http://jsfiddle.net/7s50k104/
Simple for loop with Array.prototype.splice will do the trick:
for (var i = 0; i < data.length; i++) {
if (i == 0 || data[i-1].lastname[0] !== data[i].lastname[0]) {
data.splice(i, 0, {title: data[i].lastname[0]});
i++;
}
}
Demo. Check the demo below.
var data = [
{"lastname":"Apple"},
{"lastname":"Banana"},
{"lastname":"Bob"},
{"lastname":"Car"},
{"lastname":"Christ"},
{"lastname":"Dart"},
{"lastname":"Dog"}
];
for (var i = 0; i < data.length; i++) {
if (i == 0 || data[i-1].lastname[0] !== data[i].lastname[0]) {
data.splice(i, 0, {title: data[i].lastname[0]});
i++;
}
}
alert(JSON.stringify( data, null, 4 ));
[
{"task":"test","created":"/Date(1291676980607)/"},
{"task":"One More Big Test","created":"/Date(1291677246057)/"},
{"task":"New Task","created":"/Date(1291747764564)/"}
]
I looked on here, and someone had the same sort of question, but the "checked" correct answer was that it will be different on IE if the item is deleted, which would be fine. My issue is, those items above are stored, but when i go and grab them, iterate, and return, the items are reversed and the created is at the 0 index and task is at 1. Also, i need to return this as JSON.
Here is my basic JS (value == an int the user is passing in):
outputJSON = {};
for(x in json[value]){
outputJSON[x] = _objectRevival(json[value][x]);
}
return outputJSON;
That returns:
created: Mon Dec 06 2010 15:09:40 GMT-0800 (Pacific Standard Time)
task: "test"
The order of the properties of an object is undefined. It is not possible to force them in a specified order. If you need them in a specific order, you can build this structure reliably using arrays:
var values = [
[["task", "test"], ["created", "/Date(1291676980607)/"]],
[["task", "One More Big Test"], ["created", "/Date(1291677246057)/"]],
[["task", "New Task"], ["created", "/Date(1291747764564)/"]]
];
Then you can iterate over your structure like this:
for (var i = 0; i < values.length; i++) {
for (var k = 0; k < values[i]; k++) {
// values[i][k][0] contains the label (index 0)
// values[i][k][1] contains the value (index 1)
}
}
To enforce a particular order for your output just replace json[value] in your for loop with an array of the object properties in the order you want to display them, in your case ["task", "created"].
The problem is that javascript objects don't store their properties in a specific order. Arrays on the other do (hence why you can get something consistent from json[0], json[1], json[2]).
If your objects will always have "task" and "created", then you can get at them in any order you want.
json[value]["task"]
and
json[value]["created"]
Update:
This should work with your existing code.
Before sending the json object:
var before = [
{"task":"test","created":"/Date(1291676980607)/"},
{"task":"One More Big Test","created":"/Date(1291677246057)/"},
{"task":"New Task","created":"/Date(1291747764564)/"}
];
var order = [];
for (var name in before[0]) {
order.push(name); // puts "task", then "created" into order (for this example)
}
Then send your json off to the server. Later when you get the data back from the server:
var outputJSON = {};
for (var x in order) {
if (order.hasOwnProperty(x)) {
outputJSON[order[x]] = _objectRevival(json[value][order[x]]); // I'm not sure what _objectRevival is...do you need it?
}
}
return outputJSON;
var items = ["bag", "book", "pen", "car"];
items.reverse();
This will result in the following output:
car , pen, book, bag
Even if you have JSON array it will reverse.