I need to create an array of array. It is worth noting that the database is very large and that if any attribute does not have a corresponding value, it sends an empty string. I've tried with map and reduce but I wasn't successful:
Any help will be appreciated.
Below I show an example of the expected output:
outputExpected = [
["id", 1, 2],
["name", "name1", "name2"],
["price", 6.95, 998.95],
["promoPrice", 5.91, 333.91],
["category", "test1 | test2", "test3 | test4"],
]
Any way to solve this problem performatically?
this is my code:
let arrayObj = [{
"id": 1,
"name": "name1",
"price": 6.95,
"promoPrice": 5.91,
"category": ["test1, test2"]
},
{
"id": 2,
"name": "name2",
"price": 998.95,
"promoPrice": 333.91,
"category": ["test3, test4"]
}
]
const headers = ["id", "name", "price", "promoPrice", "category"]
const result1 = headers.concat(arrayObj.map((obj) => {
return headers.reduce((arr, key) => {
arr.push(obj[key]) return arr;
}, [])
}))
console.log(result1)Reduce the array to a Map. On each iteration convert the object to an array of [key, value] pairs using Object.entries(). Use Array.forEach() to iterate the entries and add them to the map. Convert the Map's values iterator to an array using Array.from():
const arr = [{"id":1,"name":"name1","price":6.95,"promoPrice":5.91,"category":["test1", "test2"]},{"id":2,"name":"name2","price":998.95,"promoPrice":333.91,"category":["test3", "test4"]}]
const result = Array.from(arr.reduce((acc, o) => {
Object.entries(o)
.forEach(([k, v]) => {
if(!acc.has(k)) acc.set(k, [k])
acc.get(k).push(Array.isArray(v) ? v.join(' | ') : v)
})
return acc
}, new Map()).values())
console.log(result)You could simply map the value and check if an item is an array, then take the joined values or the value itself.
const
data = [{ id: 1, name: "name1", price: 6.95, promoPrice: 5.91, category: ["test1, test2"] }, { id: 2, name: "name2", price: 998.95, promoPrice: 333.91, category: ["test3, test4"] }],
headers = ["id", "name", "price", "promoPrice", "category"],
result = data
.reduce(
(r, o) => headers.map((k, i) => [
...r[i],
Array.isArray(o[k]) ? o[k].join(' | ') : o[k]
]),
headers.map(k => [k]),
);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }construct one init array with all possible keys with the wanted order, then uses Array.reduce and Array.forEach to Array.push value for per key based on its index.
const arrayObj = [
{
"id":1,
"name":"name1",
"price":6.95,
"promoPrice":5.91,
"category":["test1", "test2"]
},
{
"id":2,
"name":"name2",
"price":998.95,
"promoPrice":333.91,
"category":["test3", "test4"]
}
]
function ConvertToArray2D (items) {
let init = [['id'], ['name'], ['price'], ['promoPrice'], ['category']]
if (!items) return init
return arrayObj.reduce((pre, cur) => {
init.forEach((key, index) => {
pre[index].push(Array.isArray(cur[key[0]]) ? cur[key[0]].join('|') : cur[key[0]])
})
return pre
}, init.slice())
}
console.log(ConvertToArray2D(arrayObj))