Develop Reference

Javascript ForEach on Array of Arrays

I am looping through a collection of blog posts to firstly push the username and ID of the blog author to a new array of arrays, and then secondly, count the number of blogs from each author. The code below achieves this; however, in the new array, the username and author ID are no longer separate items in the array, but seem to be concatenated into a single string. I need to retain them as separate items as I need to use both separately; how can I amend the result to achieve this?
var countAuthors = [];
blogAuthors = await Blog.find().populate('authors');
blogAuthors.forEach(function(blogAuthor){
countAuthors.push([blogAuthor.author.username, blogAuthor.author.id]);
})
console.log(countAuthors);
// Outputs as separate array items, as expected:
// [ 'author1', 5d7eed028c298b424b3fb5f1 ],
// [ 'author2', 5dd8aa254d74b30017dbfdd3 ],
var result = {};
countAuthors.forEach(function(x) {
result[x] = (result[x] || 0) + 1;
});
console.log(result);
// Username and author ID become a single string and cannot be accessed as separate array items
// 'author1,5d7eed028c298b424b3fb5f1': 15,
// 'author2,5dd8aa254d74b30017dbfdd3': 2,
Update:
Maybe I can explain a bit further WHY on what to do this. What I am aiming for is a table which displays the blog author's name alongside the number of blogs they have written. However, I also want the author name to link to their profile page, which requires the blogAuthor.author.id to do so. Hence, I need to still be able to access the author username and ID separately after executing the count. Thanks

You could use String.split().
For example:
let result = 'author1,5d7eed028c298b424b3fb5f1'.split(',')
would set result to:
['author1' , '5d7eed028c298b424b3fb5f1']
You can then access them individually like:
result[1] //'5d7eed028c298b424b3fb5f1'

Your issue is that you weren't splitting the x up in the foreach callback, and so the whole array was being converted to a string and being used as the key when inserting into the results object.
You can use array destructuring to split the author name and blog id, and use them to optionally adding a new entry to the result object, and then update that result.
countAuthors = [
['author1', 'bookId1'],
['author2', 'bookId2'],
['author1', 'bookId3'],
['author1', 'bookId4'],
['author2', 'bookId5']
]
var result = {};
countAuthors.forEach(([author, id]) => {
if (result[author] === undefined) {
result[author] = {count: 0, blogIds: []};
}
result[author].count += 1;
result[author].blogIds.push(id);
});
console.log(result);

Making a Search Filter with JQuery?

So I have a Table made from some json data...
{
"AKH":{
"name": "Amonkhet",
"code": "AKH"
"cards": [
{
"artist": "Izzy",
"cmc": 3,
"colorIdentity": [
"W"
],
"colors": [
"White"
],
"id": "df3a6e0336684c901358f3ff53ec82ff5d7cdb9d",
"imageName": "gideon of the trials",
"layout": "normal",
"loyalty": 3,
"manaCost": "{1}{W}{W}",
"multiverseid": 426716,
"name": "Gideon of the Trials",
"number": "14",
"rarity": "Mythic Rare",
"subtypes": [
"Gideon"
],
"text": "+1: Until your next turn, prevent all damage target permanent would deal.\n0: Until end of turn, Gideon of the Trials becomes a 4/4 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.\n0: You get an emblem with \"As long as you control a Gideon planeswalker, you can't lose the game and your opponents can't win the game.\"",
"type": "Planeswalker — Gideon",
"types": [
"Planeswalker"
]
},
The Table row ends up looking like this for each of the cards. at the moment I only Attach the ID, Card name, and Mana Cost to each row
<td><a href="#" onclick="showInfo(this.id)"
id="df3a6e0336684c901358f3ff53ec82ff5d7cdb9d">Gideon of the Trials</a></td>
Now I want to search through these cards. (Keep in mind there are over 17,000 different cards that will be on this list) I can get it to find the things.. But I'm having several different issues... Either it finds them all but doesn't hide the rest of the list, or it hides the whole list and only displays one of the found cards.
So question A... What am I missing to make the search work correctly?
$(document).on('change', 'input[type=checkbox]', function() {
var lis = $('.cardsRow')
$('input[type=checkbox]').filter(':checked').each(function(){
filterKeyB = $(this).attr('id')
filterKeyA = $(this).attr('name')
$.each(json, function(setCode, setListing) {
$.each(setListing.cards,function(cardNum, cardListing){
var x = Object.keys(cardListing)
var y = Object.keys(cardListing).map(function (key){
return cardListing[key]
})
for (i = 0; (i < x.length); i++) {
if(x[i] === filterKeyA){
if (y[i] instanceof Array){
var holder = y[i]
var valueArr =[]
for(var k = 0; k < holder.length; k++){
valueArr = holder.join('|').toLowerCase().split('|')
var foundIt = valueArr.includes(filterKeyB)
}
}else{
var stringy = y[i]
var stringyA= stringy.toLowerCase().replace(/\s/g, '')
if (stringyA === filterKeyB){
var foundIt = true
}
}
if(foundIt === true){
$winner = cardListing.name
for (k = 0; (k < lis.length); k++){
if (lis[k].innerText.indexOf($winner) != -1) {
$(lis[k]).show()
}
}
}
}
}
})
Question B... Since you are already here... Would it be better practice to attach the data that can be searched to the element itself? Maybe just the most searched (Like Name and Mana) and have more advanced queries go through the data again?

I don't understand why the code isn't working or even how it works, it looks like it references some functions that aren't defined in the sample. But I can share with you a really simple/intuitive way to filter stuff, I hope you find it useful.
Native filter method is so useful for what you're trying to do, it takes a callback that takes current element as an arg and returns true or false, if true, the element is included in the new array it produces.
But filter only takes one function, and you have many filters, so let's make a function that combines many filter Fns together into one fn, so you can pass them in all at once:
const combineFilters = (...fns) => val => fns.reduce((prev, curr) => prev || curr(val), false);
OK, how about storing the names of the filter functions as keys in an object so we can reference them using a string? That way we could give each checkbox an ID corresponding to the name of the filter function they are supposed to apply, and makes things really easy to implement (and read):
const filterFns = {
startsWithG(card) {
return card.name[0] === 'G';
},
//etc.
};
OK, time to get the IDs of all the checkboxes that are clicked, then map them into an array of functions.
const filters = $('input[type=checkbox]')
.filter(':checked')
.map((e, i) => $(i).attr('id'))
.get()
.map(fnName => filterFns[fnName])
(Assume the relevant data is stored in a var called...data.) We can use combineFilters combined with filters (array of Fns) to activate all of the relevant filters, then map the resulting array of matching objects into the HTML of your choosing.
const matches = data.cards
.filter(combineFilters(...filters))
.map(card => `<div>${card.name}</div>` );
Then time to update DOM with your matches!
As others have noted, if you need to do any more complicated filtering on objects or arrays, lodash library is your friend!

List array into Javascript array?

Goal:
Pass the following tweet to visualization tool and display tweet on the UI.
Setup:
I'm getting the following 'List' on my UI. I just want to convert this list to javascript array (so that I can pass it to Visualization tools). I have concat'd 'qqq' for end of every field to identify where it ends.
Tweet:
[*high-pitched yelp* http://t.co/qaluND2Lu3qqq, neutralqqq, 0qqq,
I checked in at Starbucks on #Yelp http://t.co/8wRVos8STjqqq, negativeqqq, -0.159316qqq,
i would like to thank yelp for not helping me find any club around santa monica that plays progressive edm / progressive tranceqqq, positiveqqq, 0.372338qqq,
Nice long bar table & upstairs option (# Social Kitchen & Brewery) on #Yelp http://t.co/uhQB003NTiqqq, positiveqqq, 0.567625qqq]
Question:
How do I split by 'qqq' and then put it in a javascript array?
I have tried doing the following:
var str = "*high-pitched yelp* http://t.co/qaluND2Lu3qqq, neutralqqq, 0qqq";
var res = str.split("qqq");
But the method adds more one comma (,) at the end of every qqq. I'm confused.
Can someone help?

Update 2
It might be best to just build a new clean array, without any undefined values.
var str = "*high-pitched yelp* http://t.co/qaluND2Lu3qqq, neutralqqq, 0qqq",
myArray = str.split('qqq'),
newArray = new Array();
for ( i = 0; i < myArray.length; i++ ) { // Assuming array is built starting with the key 0
// Denote any array element that is undefined, or nonsensical white-space
if ( myArray[i] !== "" && myArray[i] !== undefined && myArray[i] !== " " ) {
newArray.push(myArray[i]);
}
}
myArray = newArray;
console.log(myArray);

Load JSON array from a database SQLITE

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/ .

How do i reverse JSON in JavaScript?

[
{"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.