Flat array to tree Javascript - javascript

Looking for a javascript or typescript solution to turn this array of sql data into a tree structure:
Some other solutions I've tried set the id as a property in the expected array but not the key of the object like in the expected solution.
const sqlData = [
{ id: 1, label: 'root', parentId: 0 },
{ id: 2, label: 'ant', parentId: 1 },
{ id: 3, label: 'cat', parentId: 1 },
{ id: 4, label: 'bear', parentId: 3 },
{ id: 5, label: 'dog', parentId: 3 },
{ id: 6, label: 'elephant', parentId: 5 },
{ id: 7, label: 'frog', parentId: 1 },
];
const expected = [
{
1: {
label: 'root',
children: [
{
2: {
label: 'ant',
children: [],
},
},
{
3: {
label: 'cat',
children: [
{
4: {
label: 'cat',
children: [],
},
},
{
5: {
label: 'dog',
children: [
{
6: {
label: 'elephant',
children: [],
},
},
],
},
},
],
},
},
{
7: {
label: 'frog',
children: [],
},
},
],
},
},
];

This can be done with O(n) time complexity by leveraging object references. By creating a children array on each element and then adding the correct child to its parent's children array, you can accomplish building the whole tree.
const sqlData=[{id:1,label:"root",parentId:0},{id:2,label:"ant",parentId:1},{id:3,label:"cat",parentId:1},{id:4,label:"bear",parentId:3},{id:5,label:"dog",parentId:3},{id:6,label:"elephant",parentId:5},{id:7,label:"frog",parentId:1}];
const parentMap = {};
const root = [];
// Map parent positions
sqlData.forEach((el, i) => {
parentMap[el.id] = i;
el.children = [];
});
sqlData.forEach(({ id, parentId, label, children }) => {
const insert = { [id]: { label, children } };
if (parentId === 0) {
root.push(insert);
return;
}
sqlData[parentMap[parentId]].children.push(insert);
});
console.log(root);

Related

search an item in multidimentionnal array

I'm trying to find an element on a multidimentionnal array usin JAVASCRIPT function, but I get error
This is my array's data:
export const datas = [
{
id: 1,
firstName: 'John',
tables: [
{ ID: 11, title: 'Lorem' },
{ ID: 12, title: 'Ipsum' },
],
},
{
id: 2,
firstName: 'Doe',
tables: [
{
ID: 22,
title: 'Arke',
nodes: [{ name: 'Name1' }, { name: 'Name2' }, { name: 'Name3' }],
},
{ ID: 23, title: 'Korem' },
],
},
{
id: 3,
firstName: 'Brad',
tables: [
{
ID: 30,
title: 'Mern',
nodes: [{ name: 'Name4' }, { name: 'Name5' }, { name: 'Name6' }],
},
{
ID: 31,
title: 'Full',
nodes: [{ name: 'Name7' }, { name: 'Name8' }, { name: 'Name9' }],
},
],
},
];
I've tried a reccursive function but it's not work, this is my code :
export const findById = (arr, id) => {
for (let o of arr) {
if (o.tables.length > 0) {
let a = findById(o.tables.nodes, 'id');
console.log(a);
}
}
};
I want to print the Object with ID 22, the problem is that I don't have the same structure in each dimension, and it still confuse me..
My Input : 22
My output :
{
ID: 22,
title: 'Arke',
nodes: [{ name: 'Name1' }, { name: 'Name2' }, { name: 'Name3' }],
},
Have you an idea how to edit my function to get my input's response ?
Your recursive function wasn't too far off, you need to check if the item as a tables first before recursively calling it again. And then finally just check the ID in the loop.
eg..
const datas=[{id:1,firstName:"John",tables:[{ID:11,title:"Lorem"},{ID:12,title:"Ipsum"}]},{id:2,firstName:"Doe",tables:[{ID:22,title:"Arke",nodes:[{name:"Name1"},{name:"Name2"},{name:"Name3"}]},{ID:23,title:"Korem"}]},{id:3,firstName:"Brad",tables:[{ID:30,title:"Mern",nodes:[{name:"Name4"},{name:"Name5"},{name:"Name6"}]},{ID:31,title:"Full",nodes:[{name:"Name7"},{name:"Name8"},{name:"Name9"}]}]}];
function findById(arr, ID) {
for (const a of arr) {
if (a.tables) {
const r = findById(a.tables, ID);
if (r) return r;
}
if (a.ID === ID) return a;
}
}
console.log(findById(datas, 22));
if you just need the nested data you can use flatMap and find
const findById = (arr, id) =>
arr
.flatMap(d => d.tables)
.find(t => t.ID === id)
const datas = [{
id: 1,
firstName: 'John',
tables: [{
ID: 11,
title: 'Lorem'
},
{
ID: 12,
title: 'Ipsum'
},
],
},
{
id: 2,
firstName: 'Doe',
tables: [{
ID: 22,
title: 'Arke',
nodes: [{
name: 'Name1'
}, {
name: 'Name2'
}, {
name: 'Name3'
}],
},
{
ID: 23,
title: 'Korem'
},
],
},
{
id: 3,
firstName: 'Brad',
tables: [{
ID: 30,
title: 'Mern',
nodes: [{
name: 'Name4'
}, {
name: 'Name5'
}, {
name: 'Name6'
}],
},
{
ID: 31,
title: 'Full',
nodes: [{
name: 'Name7'
}, {
name: 'Name8'
}, {
name: 'Name9'
}],
},
],
},
];
console.log(findById(datas, 22))
js has amazing array options https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
the ones which will help you most are probably:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap
here are some examples
// get the base with id 22
const baseWith22ID = datas.filter(f => f.tables.filter(s => s.id = 22))
// (i guess you want this one) get all elements with id 22
const onlyElementsWith22ID = datas.flatMap(f => f.tables.filter(s => s.id = 22))

How to get list of parents id in json object

My nested json array looks like:
[
{
id: 1,
name: "Mike",
children: [
{ id: 2, name: "MikeC1" },
{ id: 3, name: "MikeC2" },
{
id: 4, name: "MikeC3",
children: [{ id: 5, name: "MikeCC1" }]
},
]
},
{
id: 6,
name: "Json",
children: [
{ id: 7, name: "JsonC1" },
{ id: 8, name: "JsonC2" },
{
id: 9, name: "JsonC3",
children: [{ id: 10, name: "JsonCC1" },{ id: 11, name: "JsonCC2" }]
},
]
}
]
Now I get a id like "11"
then get the parent ids array in json like [6,9,11]
How to do?
var id = 11
console.log(findParent(id))
//result is [6,9,11]
You need to do recursive search
const persons = [
{
id: 1,
name: "Mike",
children: [
{ id: 2, name: "MikeC1" },
{ id: 3, name: "MikeC2" },
{
id: 4, name: "MikeC3",
children: [{ id: 5, name: "MikeCC1" }]
},
]
},
{
id: 6,
name: "Json",
children: [
{ id: 7, name: "JsonC1" },
{ id: 8, name: "JsonC2" },
{
id: 9, name: "JsonC3",
children: [{ id: 10, name: "JsonCC1" },{ id: 11, name: "JsonCC2" }]
},
]
}
];
function searchRecursive(items, id) {
const allIds = [];
items.forEach(item => {
if(item.id === id) {
allIds.push(item.id);
}
else if(item.children) {
const ids = searchRecursive(item.children, id);
if(ids.length) allIds.push(item.id);
ids.forEach(id => allIds.push(id));
}
});
return allIds;
}
console.log(searchRecursive(persons, 11));

How to flat tree, auto generation parent?

I want to keep the parent-child relationship of the tree node.
I have a JSON tree, like this
{
id: null,
children: [
{
id: 1,
children: [
{
id: 11,
children: [
{
id: 111
children: []
}
]
},
{
id: '12',
children: []
},
]
},
{
id: '2',
children: [
{
id: '21',
children: []
},
{
id: '22',
children: [
{
id: '221',
children: []
}
]
},
]
},
]
}
I want flat the tree, like this
[
{ id: 1, parent: null,},
{ id: 11, parent: 1, },
{ id: 111, parent: 11, },
{ id: 2, parent: null, },
{ id: 21, parent: 2, },
...
]
parent automatic generated
Is there any good way?
You could use flatMap method and create recursive function that will return 1D array as a result.
const data = {"id":null,"children":[{"id":1,"children":[{"id":11,"children":[{"id":111,"children":[]}]},{"id":"12","children":[]}]},{"id":"2","children":[{"id":"21","children":[]},{"id":"22","children":[{"id":"221","children":[]}]}]}]}
const flatten = (data, parent = null) =>
data.flatMap(({ id, children }) => ([
{ id, parent },
...flatten(children, id)
]))
const result = flatten(data.children);
console.log(result)
You could get the object and return an array of the flat children.
const
getFlat = ({ id, children = [] }) =>
children.flatMap(o => [{ id: o.id, parent: id }, ...getFlat(o)]);
var data = { id: null, children: [{ id: 1, children: [{ id: 11, children: [{ id: 111, children: [] }] }, { id: '12', children: [] }] }, { id: '2', children: [{ id: '21', children: [] }, { id: '22', children: [{ id: '221', children: [] }] }] }] },
flat = getFlat(data);
console.log(flat);
.as-console-wrapper { max-height: 100% !important; top: 0; }
If compatbility with Internet Explorer is important, then the following approach which avoids the need for Array#flatMap might suit:
const input={id:null,children:[{id:'1',children:[{id:'11',children:[{id:'111',children:[]}]},{id:'12',children:[]}]},{id:'2',children:[{id:'21',children:[]},{id:'22',children:[{id:'221',children:[]}]}]}]};
const result = [];
// Define recursive function to walk through the data tree
// and produce a flat array of required data
const recurse = (item, parent) => {
// Only add item to result if it has valid id
if (item.id) {
result.push({
id: item.id,
parent: parent ? parent.id : null
});
}
// Iterate the children of this item, traversing and
// processing them in the same way
item.children.forEach(child => recurse(child, item))
}
recurse(input);
console.log(result);
You can use a simple recursion to achieve this
let data = {
id: 1,
name: 'a1',
children: [{
id: 2,
name: 'a2',
children: [{
id: 3,
name: 'b1',
children: []
},
{
id: 4,
name: 'b2',
children: []
}
]
}]
}
function flatten(data){
output = [];
return (function indentHandler(data, level, parent){
output.push({id: data['id'], parent: parent})
if (data['children'].length === 0){
return output;
}
level += 1;
data['children'].forEach(function(child){
return indentHandler(child, level, data.name);
});
return output;
})(data, 0, null);
}
flatten(data);
use recursion
var tree = {
id: null,
children: [{
id: 1,
children: [{
id: 11,
children: [{
id: 111,
children: []
}]
},
{
id: '12',
children: []
},
]
},
{
id: '2',
children: [{
id: '21',
children: []
},
{
id: '22',
children: [{
id: '221',
children: []
}]
},
]
}
]
};
var flat = [];
function flatArray(arr, parentId) {
arr.forEach(function(el) {
flat.push({
id: el.id,
parent: parentId || null
});
if (el.children)
flatArray(el.children, el.id);
});
}
flatArray(tree.children, 0)
console.log(flat);

Find Object inside an Array of nested Objects (Lodash / Javascript / Typescript) [duplicate]

This question already has answers here:
javascript - In an array of objects, returns objects where ANY value matches a specific string
(5 answers)
Closed 4 years ago.
Lets say have an Array of Objects that looks like this:
let example = [
{
children: [{
data: { id: 2, group: 1001, name: "Audi" },
}],
data: { id: 1, group: 1000, name: "Cars" }
},
{
children: [{
data: { id: 4, group: 1003, name: "Airbus A320" },
}],
data: { id: 3, group: 1002, name: "Planes" }
},
{
children: [{
data: { id: 6, group: 1005, name: "Departed" }
}],
data: { id: 5, group: 1006, name: "movies" }
}
]
In my application the User selects a Tablerow and i get the selected Row Information aka the 'data' object e.g.
{ id: 2, group: 1001, name: "Audi" }
Now i want to find that selected data object based on the Id in my Array using lodash or javascript/typescript.
How would i achive that? The children Array causes me problems.
EDIT: The Child of a Child should also be found.
{
children: [{
children: [{
data: {id : 7, group 1001, name: "A8"},
children: [{...}]
}],
data: { id: 2, group: 1001, name: "Audi" },
}],
data: { id: 1, group: 1000, name: "Cars" }
}
/** find by id data using recursion */
function findById(data, id) {
for (const datum of data) {
if (datum.data.id == id) return datum
if (datum.children) {
let result = findById(datum.children, id)
if (result) return result
}
}
}
let example = [{
children: [{
data: {
id: 2,
group: 1001,
name: "Audi"
},
}],
data: {
id: 1,
group: 1000,
name: "Cars"
}
},
{
children: [{
data: {
id: 4,
group: 1003,
name: "Airbus A320"
},
}],
data: {
id: 3,
group: 1002,
name: "Planes"
}
},
{
children: [{
data: {
id: 6,
group: 1005,
name: "Departed"
}
}],
data: {
id: 5,
group: 1006,
name: "movies"
}
}
]
console.log(findById(example, 2))

Return a set of documents with all sub-arrays containing a given value in loopback or nodejs

How do I return a set of documents that has sub-arrays that matches common values. To better explain, consider the following data:
[
{
Category: 1,
Products: [
{
Name: 'ABC',
ColorCode:[1,2,3,4,5]
},
{
Name: 'DEF',
ColorCode:[1,2,3,4,5,6]
},
{
Name: 'GHI',
ColorCode:[1,2,3,4,6,7]
}
]
},
{
Category: 2,
Products: [
{
Name: 'JKL',
ColorCode:[4,6,7,]
},
{
Name: 'MNO',
ColorCode:[4,5,6,9,]
}
]
},
{
Category: 3,
Products: [
{
Name: 'OPQ',
ColorCode:[3,4,5,6,9,10]
},
{
Name: 'RST',
ColorCode:[2,3,5,6,9,10]
}
]
}]
The task is,
Get all the Categories with all the products containing a specific color code:
For example,
For ColorCode = 6,
Result should be:
[
{
Category: 2,
Products: [
{
Name: 'JKL',
ColorCode:[4,6,7,]
},
{
Name: 'MNO',
ColorCode:[5,6,9,]
}
]
},
{
Category: 3,
Products: [
{
Name: 'OPQ',
ColorCode:[3,4,5,6,9,10]
},
{
Name: 'RST',
ColorCode:[2,3,5,6,9,10]
}
]
}]
For ColorCode = 4,
Result should be:
[
{
Category: 1,
Products: [
{
Name: 'ABC',
ColorCode:[1,2,3,4,5]
},
{
Name: 'DEF',
ColorCode:[1,2,3,4,5,6]
},
{
Name: 'GHI',
ColorCode:[1,2,3,4,6,7]
}
]
},
{
Category: 2,
Products: [
{
Name: 'JKL',
ColorCode:[4,6,7,]
},
{
Name: 'MNO',
ColorCode:[4,5,6,9,]
}
]
}]
For ColorCode = 7,
Result should be an empty array:
[]
Thanks in advance.
You're looking for Array.prototype.filter.
// filter out categories that don't contain color code 4
categories.filter(function(category) {
return category.products.filter(containsColor(4)) > 0;
});
function containsColor(colorCode) {
return function(product) {
return product.ColorCode.indexOf(colorCode) >= 0;
};
}

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