Develop Reference

Reverse Traverse a hierarchy

I have a hierarchy of objects that contain the parent ID on them. I am adding the parentId to the child object as I parse the json object like this.
public static fromJson(json: any): Ancestry | Ancestry[] {
if (Array.isArray(json)) {
return json.map(Ancestry.fromJson) as Ancestry[];
}
const result = new Ancestry();
const { parents } = json;
parents.forEach(parent => {
parent.parentId = json.id;
});
json.parents = Parent.fromJson(parents);
Object.assign(result, json);
return result;
}
Any thoughts on how to pull out the ancestors if I have a grandchild.id?
The data is on mockaroo curl (Ancestries.json)
As an example, with the following json and a grandchild.id = 5, I would create and array with the follow IDs
['5', '0723', '133', '1']
[{
"id": "1",
"name": "Deer, spotted",
"parents": [
{
"id": "133",
"name": "Jaime Coldrick",
"children": [
{
"id": "0723",
"name": "Ardys Kurten",
"grandchildren": [
{
"id": "384",
"name": "Madelle Bauman"
},
{
"id": "0576",
"name": "Pincas Maas"
},
{
"id": "5",
"name": "Corrie Beacock"
}
]
},

There is perhaps very many ways to solve this, but in my opinion the easiest way is to simply do a search in the data structure and store the IDs in inverse order of when you find them. This way the output is what you are after.
You could also just reverse the ordering of a different approach.
I would like to note that the json-structure is a bit weird. I would have expected it to simply have nested children arrays, and not have them renamed parent, children, and grandchildren.
let data = [{
"id": "1",
"name": "Deer, spotted",
"parents": [
{
"id": "133",
"name": "Jaime Coldrick",
"children": [
{
"id": "0723",
"name": "Ardys Kurten",
"grandchildren": [
{
"id": "384",
"name": "Madelle Bauman"
},
{
"id": "0576",
"name": "Pincas Maas"
},
{
"id": "5",
"name": "Corrie Beacock"
}
]
}]
}]
}]
const expectedResults = ['5', '0723', '133', '1']
function traverseInverseResults(inputId, childArray) {
if(!childArray){ return }
for (const parent of childArray) {
if(parent.id === inputId){
return [parent.id]
} else {
let res = traverseInverseResults(inputId, parent.parents || parent.children || parent.grandchildren) // This part is a bit hacky, simply to accommodate the strange JSON structure.
if(res) {
res.push(parent.id)
return res
}
}
}
return
}
let result = traverseInverseResults('5', data)
console.log('results', result)
console.log('Got expected results?', expectedResults.length === result.length && expectedResults.every(function(value, index) { return value === result[index]}))

Group and count values in an array

I have an array with objects, like the following.
b = {
"issues": [{
"fields": {
"status": {
"id": "200",
"name": "Backlog"
}
}
}, {
"fields": {
"status": {
"id": "202",
"name": "close"
}
}
}, {
"fields": {
"status": {
"id": "201",
"name": "close"
}
}
}]
};
I want to count how many issues have status close, and how many have backlog. I'd like to save the count in a new array as follows.
a = [
{Name: 'Backlog', count: 1},
{Name: 'close', count: 2}
];
I have tried the following.
b.issues.forEach(function(i) {
var statusName = i.fields.status.name;
if (statusName in a.Name) {
a.count = +1;
} else {
a.push({
Name: statusName,
count: 1
});
}
});
That however doesn't seem to be working. How should I implement this?

This is a perfect opportunity to use Array#reduce. That function will take a function that is applied to all elements of the array in order and can be used to accumulate a value. We can use it to accumulate an object with the various counts in it.
To make things easy, we track the counts in an object as simply {name: count, otherName: otherCount}. For every element, we check if we already have an entry for name. If not, create one with count 0. Otherwise, increment the count. After the reduce, we can map the array of keys, stored as keys of the object, to be in the format described in the question. See below.
var b = {
"issues": [{
"fields": {
"status": {
"id": "200",
"name": "Backlog"
}
}
}, {
"fields": {
"status": {
"id": "202",
"name": "close"
}
}
}, {
"fields": {
"status": {
"id": "201",
"name": "close"
}
}
}]
};
var counts = b.issues.reduce((p, c) => {
var name = c.fields.status.name;
if (!p.hasOwnProperty(name)) {
p[name] = 0;
}
p[name]++;
return p;
}, {});
console.log(counts);
var countsExtended = Object.keys(counts).map(k => {
return {name: k, count: counts[k]}; });
console.log(countsExtended);
.as-console-wrapper {
max-height: 100% !important;
}
Notes.
Array#reduce does not modify the original array.
You can easily modify the function passed to reduce to for example not distinguish between Backlog and backlog by changing
var name = c.fields.status.name;
into
var name = c.fields.status.name.toLowerCase();
for example. More advanced functionality can also easily be implemented.

Using ES6 Arrow functions you can do it with minimum syntax
var b = {
"issues": [{
"fields": {
"status": {
"id": "200",
"name": "Backlog"
}
}
}, {
"fields": {
"status": {
"id": "202",
"name": "close"
}
}
}, {
"fields": {
"status": {
"id": "201",
"name": "close"
}
}
}]
};
var countOfBackLog = b.issues.filter(x => {
return x.fields.status.name === "Backlog"
}).length
var countOfClose = b.issues.filter(x => {
return x.fields.status.name === "close"
}).length
a =[{Name: 'Backlog', count : countOfBackLog}, {Name: 'close', count : countOfClose}]
More about arrow functions here

You can write like this. It is dynamic.
var a = {};
for(var key in b["issues"]){
if(!a.hasOwnProperty(b["issues"][key].fields.status.name)){
a[b["issues"][key].fields.status.name] = 1;
}else{
a[b["issues"][key].fields.status.name] = a[b["issues"][key].fields.status.name]+1;
}
}
var c = [];
for(var key1 in a){
c.push({
name : key1,
count : a[key1]
});
}

Something like this should do the trick. Simply iterate over your data, keep 2 counters with the number of each type of issue, and create the data format you want in the end. Try it live on jsfiddle.
var b = {
"issues": [{
"fields": {
"status": {
"id": "200",
"name": "Backlog"
}
}
}, {
"fields": {
"status": {
"id": "202",
"name": "close"
}
}
}, {
"fields": {
"status": {
"id": "201",
"name": "close"
}
}
}]
};
var data = [];
for(var issue of b.issues){
var entryFound = false;
var tempObj = {
name: issue.fields.status.name,
count: 1
};
for(var item of data){
if(item.name === tempObj.name){
item.count++;
entryFound = true;
break;
}
}
if(!entryFound){
data.push(tempObj);
}
}
console.log(data);

In JSON Object parent key name remove and Include its inner content

This is my JSON Object in this i want to remove "item" key from json and want to keep its inner object include with "children" and its tree like JOSN. How can I do this?
[
{
"item": {
"id": 11865,
"parentid": null,
"levelid": 63,
"name": "Total"
},
"children": [
{
"item": {
"id": 10143,
"parentid": 11865,
"levelid": 19,
"name": "Productive"
}
}
]
}
]

If I'm understanding what you want your object to look like after correctly, then this should do the trick:
var arrayOfObjects = [
{
"item": {
"id": 11865,
"parentid": null,
"levelid": 63,
"name": "Total"
},
"children": [
{
"item": {
"id": 10143,
"parentid": 11865,
"levelid": 19,
"name": "Productive"
}
}
]
}
]
arrayOfObjects.forEach(function(obj) {
obj.id = obj.item.id;
obj.parentid = obj.item.parentid;
obj.levelid = obj.item.levelid;
obj.name = obj.item.name;
delete obj.item;
});
All this is doing is manually moving the data from obj.item to obj and then deleting obj.item entirely.

I would do this:
//your original array of objects
var array = [{
"item": {
"id": 11865,
"parentid": null,
"levelid": 63,
"name": "Total"
},
"children": [
{
"item": {
"id": 10143,
"parentid": 11865,
"levelid": 19,
"name": "Productive"
}
}
]
}, ...];
array.forEach(function(parent) {
flattenKey(parent, 'item');
});
function flattenKey(parent, keyName) {
var section = parent[keyName];
var child = section ? section : {};
var keys = Object.keys(child);
keys.forEach(function(key) {
parent[key] = child[key];
})
delete parent[keyName];
}
basically, the function flattenKey would flatten any key for a given object (given its key).
logic is similar to other solutions here: iterate through child keys and assign their values to the parent object (flattening).
then it deletes the child key after step 1.

try
objArray = objArray.map( function(value){
var item = value.item;
for( var key in item )
{
value[key] = item[key];
}
delete value.item;
return value;
});
DEMO
Explanation
1) Use map to iterate on each item (value) of this given array objArray.
2) Get the item property of value, assign them to value directly
3) Finally delete the item property of the value.
Faster option
objArray = objArray.map( function(value){
var item = value.item;
var itemKeys = Object.keys(item);
for( var counter = 0; counter < itemKeys.length; counter++ )
{
value[itemKeys[counter]] = item[itemKeys[counter]];
}
delete value.item;
return value;
});

You can use a recursion, which keeps the content of item and adds the children property as well.
function delItem(a, i, aa) {
var children = a.children;
if (a.item) {
aa[i] = a.item;
aa[i].children = children;
delete a.item;
}
Array.isArray(children) && children.forEach(delItem);
}
var array = [{ "item": { "id": 11865, "parentid": null, "levelid": 63, "name": "Total" }, "children": [{ "item": { "id": 10143, "parentid": 11865, "levelid": 19, "name": "Productive" } }] }];
array.forEach(delItem);
document.write('<pre>' + JSON.stringify(array, 0, 4) + '</pre>');

Create array from complex array objects & loops in javascript

I currently have a complex orders array (coming from a JSON client) that contains multiple orders like this (contains 2):
0: {
"employee": "Nicole"
"total": 13
"lineItems": {
"elements": [2]
0: {
"name": "Burger"
"price": 8
}
1: {
"name": "Lamb"
"price": 6.50
}
}
}
1: {
"employee": "Dan"
"total": 11
"lineItems": {
"elements": [2]
0: {
"name": "Lamb"
"price": 4.50
}
1: {
"name": "Meatballs"
"price": 6.50
}
}
}
What I want to do is create a new array that loops through the above and creates new items array based on the name of the lineItems object above. i.e. final output looks something like this:
var items = {
"Burger" = {
"totalSpent" : 8
},
"Lamb" = {
"totalSpent" : 13
// Note this totalSpent is an iteration or sum of all "price" items where name/id = "Lamb"
},
"Meatballs" = {
"totalSpent" : 4.50
}
}
I'm more used to PHP and have tried a number of different versions of this but can't seem to get the desired output. Here's what I've got so far:
var orders = //As above//
// Initialising new array to hold my final values
var orderItems = [];
for (var i = 0, len = orders.length; i < len; i++){
for(var e = 0, leng = orders[i]['lineItems']['elements'].length; e < leng; e++){
var totalSpent = 0;
var id = orders[i]['lineItems']['elements'][e]['name'];
if (orders[id] in orderItems[id]){
// overwrite existing array item
orderItems[id]['totalSpent'] += orders[i]['lineItems']['elements'][e]['price'];
orderItems[id].push({totalSpent : orderItems[id]['totalSpent']});
}
else {
// Create new array item
orderItems.push(id);
orderItems[id].push({totalSpent : orders[i]['lineItems']['elements'][e]['price']});
}
}
}

Edit:
Had to correct your orders syntax, I added it to my answer so you can run the Javascript Snippet;
Changed the whole dot notation to bracket notation to make it easier to read and understand;
Corrected the bug about items remaining an empty array (it was in the inner for);
var orders = [
{
"employee": "Nicole",
"total": 13,
"lineItems": {
"elements": [
{
"name": "Burger",
"price": 8
},
{
"name": "Lamb",
"price": 6.50
}
]
}
},
{
"employee": "Dan",
"total": 11,
"lineItems": {
"elements": [
{
"name": "Lamb",
"price": 4.50
},
{
"name": "Meatballs",
"price": 6.50
}
]
}
}
];
var items = {};
// loop in orders array
for (var i = 0; i < orders.length; i++) {
var elements = orders[i]["lineItems"]["elements"];
// loop in orders[i]["lineItems"]["elements"] object
for (var eIndex in orders[i]["lineItems"]["elements"]) {
// Add new item if it doesn't already exist
if (!items.hasOwnProperty(elements[eIndex]["name"])) {
items[elements[eIndex]["name"]] = {"totalSpent": elements[eIndex]["price"]};
} else {
// If it exists, sum totalSpent
items[elements[eIndex]["name"]]["totalSpent"] += elements[eIndex]["price"];
}
}
}
console.log(items);
PS: To find out why I'm using bracket notation instead of dot notation, check this question, it's good to know!

First of all, there are some error in your order array, note the difference between {} (for objects) and []. Then it is just simple use of the map function to iterate over the arrays.
See your browser console (F12) for the result of this snippet
var orders = [{
"employee": "Nicole",
"total": 13,
"lineItems": {
"elements": [{
"name": "Burger",
"price": 8
}, {
"name": "Lamb",
"price": 6.50
}
]
}
}, {
"employee": "Dan",
"total": 11,
"lineItems": {
"elements": [{
"name": "Lamb",
"price": 6.50
}, {
"name": "Meatballs",
"price": 4.50
}]
}
}]
var items = {}
orders.map(function(order) {
order.lineItems.elements.map(function(elem) {
if (items[elem.name]) {
items[elem.name].totalSpent += elem.price
} else {
items[elem.name] = {"totalSpent": elem.price}
}
})
})
console.log(items)

filter result using 2 JSON

This is my saved localstorage,
[{"industry_Id":1,"merchant_id":2}]
I want to filter below result, to get HP.
{
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
}
I thought of using multiple $.each but it have to iterate few times and it's quite redundant.

I would prefer using Javascript for loop, that way you can skip iterating over every object once required element is found.
Without jQuery (using for)
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
With jQuery (using $.each)
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
var arg = [{"industry_Id":1,"merchant_id":2}];
var data = {
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
};
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
console.log(merchant);
document.writeln("<b>Without jQuery:</b><br>");
document.writeln((merchant !== null) ? "Found " + merchant['name'] : "Not found");
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
console.log(merchant_found);
document.writeln("<br><br><b>With jQuery:</b><br>");
document.writeln((merchant_found) ? "Found " + merchant_found['name'] : "Not found");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

selectors.map(function(selector) {
return data.industries.filter(function(industry) {
return industry.id == selector.industry_Id;
})[0].merchant.filter(function(merchant) {
return merchant.id == selector.merchant_id;
})[0].name;
});
// => DEF
If you want "HP", you want industry 2, not industry 1.
.filter(...)[0] is not really optimal. You could use .find(...), but that is not yet universally supported. Or you could use plain old JavaScript and write for loops instead to make it fast. Or you could use objects with ID keys instead of arrays to make lookups faster.

When it comes into a position where collection of data is what you're processing, I suggest you to take a look at underscore.js. It's not optimal choice for the best performance but it does make you code more readable and makes more sense especially when compared with loop.
Say data is a variable which stores your JSON data.
Try this:
// Given this selector criteria
var select = [{"industry_Id":1,"merchant_id":2}];
function filterByCriteria(criteria, data){
var match = [];
_.each(criteria, function(crit){
function matchIndustry(rec){ return rec.id===crit.industry_Id }
function matchMerchant(rec){ return rec.id===crit.merchant_id }
// Filter by industry id
var industry = _.first(_.where(data.industry, matchIndustry));
// Filter by merchant id
var merchant = _.where(industry.merchant, matchMerchant);
_.each(merchant, function addToMatchResult(m){
match.push(m.name);
});
});
return match;
}
var filteredData = filterByCriteria(select, data);
From snippet above, any merchants which match the search criteria will be taken to the match list. Is it more readable to you?

Do you even need numerical id's? Gets super easy when you don't.
/*
{
"industry": {
"oil and gas":{
"merchant": {
"ABC": {
"name": "ABC oil"
},
"DEF": {
"name": "DEF gas"
},
"GHJ" :{
"name": "GHJ oil and gas"
}
}
},
"IT": {
"merchant": {
"Apple" : {
"name": "Apple computers"
},
"HP": {
"name": "Hewlett Packard"
},
"Google": {
"name": "Google. Maw haw haw"
}
}
}
}
}
*/
var data = '{"industry": {"oil and gas":{"merchant": {"ABC": {"name": "ABC oil"},"DEF": {"name": "DEF gas"},"GHJ" :{"name": "GHJ oil and gas"}}},"IT": {"merchant": {"Apple" : {"name": "Apple computers"},"HP": {"name": "Hewlett Packard"},"Google": {"name": "Google. Maw haw haw"}}}}}';
data = JSON.parse(data);
var merchant = data.industry['IT'].merchant['HP'];
alert(merchant.name);
//console.log(merchant.name);