javascript - Get index of Object inside Array and use it in a function

Question

In Javascript, is it possible to get the Index of the object (in an array of objects) and use it inside of the same object in a function?

For example:

const foo = [
  {
    id: 1,
    comments: getComments(this.index) // index of the object goes here
  },
  {
    id: 34,
    comments: getComments(this.index) // index of the object goes here
  },
  {
    id: 21,
    comments: getComments(this.index) // index of the object goes here
  }
]

const getComments = function(index) {
  return foo[index].id // return the ID of the actual object
}

Or is there a workaround for what I'm trying to achieve here?

question from:https://stackoverflow.com/questions/65944212/get-index-of-object-inside-array-and-use-it-in-a-function

Answer 1

Do it in two steps. First create the array of objects, then fill in the comments property by calling the function on each element.

const foo = [
  {
    id: 1,
  },
  {
    id: 34,
  },
  {
    id: 21,
  }
]

foo.forEach(el => el.comments = getComments(el));

function getComments(obj) {
  return obj.id;
}

console.log(foo);