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Convert array of structured string into multi-level object in Javascript [duplicate]

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I have an array of structured strings with have connection | as a format which self-divided into levels. I want to convert it into a structured object with multiple levels.
Input:
[
"clothes|tshirt|tshirt-for-kids",
"clothes|coat|raincoat",
"clothes|coat|leather-coat",
"clothes|tshirt|tshirt-for-men",
"clothes|tshirt|tshirt-for-men|luxury-tshirt",
]
Expected output:
{
clothes: {
tshirt: {
tshirt-for-kids: {},
tshirt-for-men: {
luxury-tshirt: {}
}
},
coat: {
raincoat: {}
leather-coat: {}
}
}
}

Very simple task - just enumerate the array and create the relevant object keys:
var myArray = [
"clothes|tshirt|tshirt-for-kids",
"clothes|coat|raincoat",
"clothes|coat|leather-coat",
"clothes|tshirt|tshirt-for-men",
"clothes|tshirt|tshirt-for-men|luxury-tshirt",
]
var result = {}, levels, current, temp;
while(myArray.length > 0)
{
levels = myArray.pop().split('|');
temp = result;
while(levels.length > 0)
{
current = levels.shift();
if(!(current in temp)) temp[current] = {};
temp = temp[current];
}
}
console.log(result);

You could try this:
const input = [
"clothes|tshirt|tshirt-for-kids",
"clothes|coat|raincoat",
"clothes|coat|leather-coat",
"clothes|tshirt|tshirt-for-men",
"clothes|tshirt|tshirt-for-men|luxury-tshirt",
];
function convertStrToObject(str, sep, obj) {
const sepIndex = str.indexOf(sep);
if (sepIndex == -1) {
obj[str] = obj[str] || {};
} else {
const key = str.substring(0, sepIndex);
obj[key] = obj[key] || {};
convertStrToObject(str.substring(sepIndex + 1), sep, obj[key]);
}
}
const all = {};
for (let i = 0; i < input.length; ++i) {
convertStrToObject(input[i], "|", all);
}
console.log(all);

Assuming you intend to collect properties, all having an empty object as leaf node.
// input
const input = [
"clothes|tshirt|tshirt-for-kids",
"clothes|coat|raincoat",
"clothes|coat|leather-coat",
"clothes|tshirt|tshirt-for-men",
"clothes|tshirt|tshirt-for-men|luxury-tshirt",
];
// Here, we collect the properties
const out = {};
// map the input array, splitting each line at |
input.map(i => i.split('|'))
.filter(a => a.length > 0) // lets not entertain empty lines in input
.forEach(a => { // process each array of property names
// start at outermost level
let p = out;
// iterate properties
for(const v of a){
// create a property if it is not already there
if(!p.hasOwnProperty(v)){
p[v] = {};
}
// move to the nested level
p = p[v];
}
});
// lets see what we have created
console.log(out);

A number of solutions have been suggested already, but I'm surprised none involves reduce() - which would seem the more idiomatic solution to me.
var array = [
"clothes|tshirt|tshirt-for-kids",
"clothes|coat|raincoat",
"clothes|coat|leather-coat",
"clothes|tshirt|tshirt-for-men",
"clothes|tshirt|tshirt-for-men|luxury-tshirt",
]
var object = array.reduce(function (object, element) {
var keys = element.split("|")
keys.reduce(function (nextNestedObject, key) {
if (!nextNestedObject[key]) nextNestedObject[key] = {}
return nextNestedObject[key]
}, object)
return object
}, {})
console.log(object)

One Liner With eval
Used eval to evaluate strings like the following:
'o["clothes"]??={}'
'o["clothes"]["tshirt"]??={}'
'o["clothes"]["tshirt"]["tshirt-for-kids"]??={}'
const
data = ["clothes|tshirt|tshirt-for-kids", "clothes|coat|raincoat", "clothes|coat|leather-coat", "clothes|tshirt|tshirt-for-men", "clothes|tshirt|tshirt-for-men|luxury-tshirt"],
arr = data.map((d) => d.split("|")),
res = arr.reduce((r, a) => (a.forEach((k, i) => eval(`r["${a.slice(0, i + 1).join('"]["')}"]??={}`)), r), {});
console.log(res)
One Liner Without eval
const
data = ["clothes|tshirt|tshirt-for-kids", "clothes|coat|raincoat", "clothes|coat|leather-coat","clothes|tshirt|tshirt-for-men", "clothes|tshirt|tshirt-for-men|luxury-tshirt"],
res = data.reduce((r, d) => (d.split("|").reduce((o, k) => (o[k] ??= {}, o[k]), r), r), {});
console.log(res)

Create new array with Average of same keys in an array of objects

I have an array of object as follows:
var arr=[ {"jan":2},{"jan":5},{"feb":3},{"feb":1}];
Their will be N number of objects with any combination keys jan & feb is just an example.
I need to find average of objects with similar keys so that resultant array looks like this :
var newArr=[{"jan":3.5},{"feb":2}];
Looking to achieve this without reduce method in JavaScript.
I tried to seperate out objects with similar keys so that ic an sum and average them and push in to a new aray. something like this :
arr.forEach(a=>{
console.log(Object.keys(a))
console.log(arr.filter(ar=>ar.hasOwnProperty(Object.keys(a)[0])))
})
But it creates multiple groups for same keys like this in console.
[ {"jan":2},{"jan":5} ]
[ {"jan":2},{"jan":5} ]
[ {"feb":3},{"feb":1} ]
[ {"feb":3},{"feb":1} ]

A code without using reduce . A bit length though but easy to understand
We are using two objects , one is to store the count of the keys and other is for storing the total of the keys.
result object has the average.
var arr=[ {"jan":2},{"jan":5},{"feb":3},{"feb":1}];
var count = {};
var total = {};
arr.forEach(obj => {
var key = Object.keys(obj)[0];
if(count.hasOwnProperty(key)){
count[key]=count[key]+1;
} else {
count[key]=1;
}
if(total.hasOwnProperty(key)){
total[key]=total[key]+obj[key];
} else {
total[key]=obj[key];
}
})
var result = {}
Object.keys(total).forEach(key => {
result[key] = total[key]/count[key];
})
console.log(result)

Similar to the answer above, but makes use of a map:
var arr=[ {"jan":2},{"jan":5},{"feb":3},{"feb":1}];
let map = new Map();
let keyCount = {};
arr.forEach(e => {
let key = Object.keys(e)[0];
let value = Object.values(e)[0];
if (map.get(key) !== undefined) {
map.set(key, map.get(key) + value);
keyCount[key] = keyCount[key] + 1;
} else {
map.set(key, value);
keyCount[key] = 1;
}
});
let newArr = [];
for (let e of map.entries()) {
let obj = {};
obj[e[0]] = e[1] / keyCount[e[0]];
newArr.push(obj);
}
console.log(newArr);

How to compare 2 array and add key if don't have

Supposed that I have two arrays to compare:
var arrOriginal={currency1: 1234, currency2: 2345};
var arrToCompare={currency1: 123};
I was trying to find the difference between the two.
Example result:
var result={currency1: 1111, currency2: 2345}
What I've tried:
Using for .. in and then substract.
for (var key in this.arrOriginal) {
this.result.push({
currency: key,
amount: format.formatCurrency(this.arrToCompare[key] - this.arrOriginal[key])
});
}
But it won't show the currency key which the second array don't have.
Any help is appreciated.

You could take a default value of zero for undefined properties of the object.
From inside to out:
Get entries from the object as an array of key/value pairs.
Map this entries and get an object with the key and a value of the difference of value and the corresponding value of the other object or zero.
Spread the object as parameters for Object.assign.
And get a new object with all objects from mapping.
var original = { currency1: 1234, currency2: 2345 },
deltas = { currency1: 123 },
result = Object.assign(
{},
...Object.entries(original).map(([k, v]) => ({ [k]: v - (deltas[k] || 0)}))
);
console.log(result);

A very simple approach is looping over the keys of arrOriginal, If that key is present in arrToCompare then substract that value else do not substract.
var arrOriginal={currency1: 1234, currency2: 2345};
var arrToCompare={currency1: 123};
var out = {}
for(var key in arrOriginal){
out[key] = arrOriginal[key] - (arrToCompare[key] || 0)
}
console.log(out)

You can use Object.entries and reduce
var arrOriginal={currency1: 1234, currency2: 2345};
var arrToCompare={currency1: 123};
let final = Object.entries(arrOriginal).reduce((op,[key,value])=>{
op[key] = value - (arrToCompare[key] || 0)
return op
},{})
console.log(final)

A very easy to understand approach would be to have an if-else statement with three branches that check if the key exists in both or either one of the original objects:
const original = { currency1: 1234, currency2: 2345 }
const toCompare = { currency1: 123 }
const result = {}
const allKeys = new Set(Object.keys(original).concat(Object.keys(toCompare)))
allKeys.forEach(k => {
if (k in original && k in toCompare) {
result[k] = original[k] - toCompare[k]
} else if (k in original) {
result[k] = original[k]
} else {
result[k] = toCompare[k]
}
})
console.log(result)

How to get all the values and keys inside an array of objects separated with comma without inbuilt methods

I have tried to retrieve all the values of an plain object which returns an array separated with comma since I am using map().
var obj = { 1: 'Banana', 2: 'Orange'};
var values = Object.keys(obj).map(function(e) {
return obj[e]
}) //returns ['Banana','Orange']
Where as I need all the values and keys as string separated by comma from below object array without using Object.values() and Object.keys
input: var items = [{1:"Banana"}, {2:"Orange"}, {3:"Apple"}]
output 1: "1,2,3" ---> keys
output 2: "Banana,Orange,Apple" --> values
Problem is when the objects are inside an array I am not getting any idea how to retrieve keys and object values separately.
Kindly help!

You can use array reduce & join
Inside reduce callback use for..in to iterate the object. [[],[]] is the accumulator & in the first array keys will be collected and in second array values will be collected.
Inside the for..in push the keys & values from each object.
Once done use join with delimiter , to create the string
var items = [{
1: "Banana"
}, {
2: "Orange"
}, {
3: "Apple"
}]
let vals = items.reduce(function(acc, curr) {
for (let keys in curr) {
acc[0].push(keys);
acc[1].push(curr[keys])
}
return acc;
}, [
[],
[]
]);
console.log(vals[0].join(','), vals[1].join(','))

You can iterate over the array and in a nested for loop iterate over the object:
var items = [{1:"Banana"}, {2:"Orange"}, {3:"Apple"}];
let keys = [];
let values = [];
for (let element of items){
for (let i in element){
keys.push(i);
values.push(element[i]);
}
}
keys = keys.join(",");
values = values.join(",");
console.log(keys);
console.log(values);

Using for ... in
const items = [{
1: "Banana"
}, {
2: "Orange"
}, {
3: "Apple"
}];
let keys = '';
let values = '';
items.forEach((x) => {
for (let y in x) {
keys = `${keys}${keys.length ? ',' : ''}${y}`;
values = `${values}${values.length ? ',' : ''}${x[y]}`;
}
});
console.log(keys);
console.log(values);
Using Object.keys() and Array.reduce
const items = [{
1: "Banana"
}, {
2: "Orange"
}, {
3: "Apple"
}];
const rets = items.reduce((tmp, x) => {
Object.keys(x).forEach((y) => {
tmp.keys = `${tmp.keys}${tmp.keys.length ? ',' : ''}${y}`;
tmp.values = `${tmp.values}${tmp.values.length ? ',' : ''}${y}`;
});
return tmp;
}, {
keys: [],
values: [],
});
console.log(rets);

With the for..in and for..of functions
const items = [{1:"Banana"}, {2:"Orange"}, {3:"Apple"}];
let keys = [];
let values = [];
for(let item of items){
for(let key in item){
keys.push(key);
values.push(item[key]);
}
}
// keys == [1, 2, 3]
// values == [Banana, Orange, Apple]
After this you can use the join function
console.log(keys.join()); // Output : "1,2,3"
console.log(values.join()); // Output : "Orange,Banana,Apple"

Convert set of object's into array item

I have several objects like this:
{'id[0]': 2}
{'url[0]': 11}
{'id[1]': 3}
{'url[1]': 14}
And I want to get something like this:
[{id:2, url:11}, {id:3, url:14}]
Also I have lodash in my project. Maybe lodash have some method for this?

You could use a regular expression for the keys and create a new object if necessary. Then assign the value to the key.
var data = [{ 'id[0]': 2 }, { 'url[0]': 11 }, { 'id[1]': 3 }, { 'url[1]': 14 }],
result = [];
data.forEach(function (a) {
Object.keys(a).forEach(function (k) {
var keys = k.match(/^([^\[]+)\[(\d+)\]$/);
if (keys.length === 3) {
result[keys[2]] = result[keys[2]] || {};
result[keys[2]][keys[1]] = a[k];
}
});
});
console.log(result);

This is an ES6 solution based on #NinaScholz solution.
I assume that the objects have only one property each, like the ones presented in the question.
Combine the array of objects to one large object using Object#assign, and convert to entries with Object.entries.
Iterate the array using Array#reduce.
Extract the original key an value from each entry using array
destructuring.
Extract the wanted key and index using a regex and array
destructuring.
Then create/update the new object at the index using object spread.
const data = [{ 'id[0]': 2 }, { 'url[0]': 11 }, { 'id[1]': 3 }, { 'url[1]': 14 }];
// combine to one object, and convert to entries
const result = Object.entries(Object.assign({}, ...data))
// extract the original key and value
.reduce((r, [k, value]) => {
// extract the key and index while ignoring the full match
const [, key, index] = k.match(/^([^\[]+)\[(\d+)\]$/);
// create/update the object at the index
r[index] = {...(r[index] || {}), [key]: value };
return r;
}, []);
console.log(result);

var arr = [{'id[0]': 2},
{'url[0]': 11},
{'id[1]': 3},
{'url[1]': 14}];
var result = [];
arr.forEach(function(e, i, a){
var index = +Object.keys(e)[0].split('[')[1].split(']')[0];//get the number inside []
result[index] = result[index] || {}; //if item is undefined make it empty object
result[index][Object.keys(e)[0].split('[')[0]] = e[Object.keys(e)[0]];//add item to object
})
console.log(result);

You can use for loop, .filter(), RegExp constructor with parameter "\["+i+"\]" where i is current index, Object.keys(), .reduce(), .replace() with RegExp /\[\d+\]/
var obj = [{
"id[0]": 2
}, {
"url[0]": 11
}, {
"id[1]": 3
}, {
"url[1]": 14
}];
var res = [];
for (var i = 0; i < obj.length / 2; i++) {
res[i] = obj.filter(function(o) {
return new RegExp("\[" + i + "\]").test(Object.keys(o))
})
.reduce(function(obj, o) {
var key = Object.keys(o).pop();
obj[key.replace(/\[\d+\]/, "")] = o[key];
return obj
}, {})
}
console.log(res);