How to optimize this transformation from array to object with specific key?-CodePudding

How to optimize this transformation from array to object with specific key?

I have this array that inside has other arrays, and I wanted to turn this array into an array of objects. I would like to do this without using this index, and the object would like it to have these specific keys. I'm new to javascript and I would like to know if the way I did it was the best way, or if I can use a Map or Reduce to do what I want.

const listaCesar = [["cesar", "1", 1], ["thiago", "2", 2], ["giuseppe", "3", 3]]

const dict = []
listaCesar.forEach(item => dict.push({name: item[0], id: item[1], age: item[2]}))

console.log(dict)

This code works and gives me the expected result, but I don't know if I did it in the best way

ExpectResult = [{name: "cesar", id: "1", age: "1"}, {name: "thiago", id: "2", age: "2"}, {name: "giuseppe", id: "3", age: "3"}]

CodePudding user response：

your solution is not bad, but I think you want something more "Elegant" so you can reduce your function to something like this:

const dict = listaCesar.map(([name, id, age]) => ({ name, id, age }));

basically with [name, id, age] you are destructuring the inner array and using those same names in the object { name, id, age } you will create a key value object with those name as keys.

const listaCesar = [
  ["cesar", "1", 1],
  ["thiago", "2", 2],
  ["giuseppe", "3", 3]
]

const dict = []
listaCesar.forEach(item => dict.push({
  name: item[0],
  id: item[1],
  age: item[2]
}))

console.log(dict);

console.log('////////////////////////////////////////');

const dict2 = listaCesar.map(([name, id, age]) => ({
  name,
  id,
  age
}));
console.log(dict2);

if you want something more performant to avoid using another structure you can reuse the same array that you have following the same approach, in this case you do not return a new array instead you reuse the same index on the array to put your new object.

const listaCesar = [
  ["cesar", "1", 1],
  ["thiago", "2", 2],
  ["giuseppe", "3", 3]
]


listaCesar.forEach(([name, id, age], i) => {
  listaCesar[i] = {
    name,
    id,
    age
  }
})

console.log(listaCesar);

CodePudding user response：

One improvement you can do is use an array to keep names of properties and loop over it to create object, so that it becomes extensible

const listaCesar = [
  ["cesar", "1", 1],
  ["thiago", "2", 2],
  ["giuseppe", "3", 3]
]
const props = ['name', 'id', 'age', ]
const dict = listaCesar.map(item => props.reduce((a, b, i) => {
  a[b] = item[i]
  return a
}, {}))

console.log(dict)