javascript - How to sort an array of objects with labels according to other array of labels?

Question

I want to sort an array of objects with labels, for example

var arrayToBeSorted = [{label: 'firstLabel', value: 123}, {label: 'secondLabel', value: 456}, {label: 'thirdLabel', value: 789}]

and an array of labels as a baseline, for example

var labels = ['secondLabel', 'thirdLabel', 'fourthLabel', 'firstLabel']

Now I want to sort my first array, so that the objects in it follow the order of labels in the second array labels.

I know basic sorting mechanism with custom comparators like

CustomComparator: function(a, b) {
  if (a[0].length > b[0].length) return -1;
  if (a[0].length < b[0].length) return 1;
  return 0;
}

but I have no idea on how to convert this.

In my research I found this solution on stackoverflow coded in ruby, but I don't know if there is a similar option in javascript.

I appreciate any help, invested quite some time on this.

Answer 1

You need to provide priority to values as per second array. here we are building a Map from second array name as key and index as priority. so you can use Map and default value and sort

var arrayToBeSorted = [{label: 'firstLabel', value: 123}, {label: 'secondLabel', value: 456}, {label: 'thirdLabel', value: 789}]
var labels = ['secondLabel', 'thirdLabel', 'fourthLabel', 'firstLabel']

let mapper = new Map(labels.map((v, i) => [v, i + 1]))

let final = arrayToBeSorted.sort((a, b) => {
  return (mapper.get(a.label) || Infinity) - (mapper.get(b.label) || Infinity)
})

console.log(final)