como usar o uniqueElementsBy no javascript es6

January 04, 2020

Returns all unique values of an array, based on a provided comparator function.

Use Array.prototype.reduce() and Array.prototype.some() for an array containing only the first unique occurrence of each value, based on the comparator function, fn. The comparator function takes two arguments: the values of the two elements being compared.

const uniqueElementsBy = (arr, fn) =>
  arr.reduce((acc, v) => {
    if (!acc.some(x => fn(v, x))) acc.push(v);
    return acc;
  }, []);

uniqueElementsBy(
  [
    { id: 0, value: 'a' },
    { id: 1, value: 'b' },
    { id: 2, value: 'c' },
    { id: 1, value: 'd' },
    { id: 0, value: 'e' }
  ],
  (a, b) => a.id == b.id
); // [ { id: 0, value: 'a' }, { id: 1, value: 'b' }, { id: 2, value: 'c' } ]

Acesse a Referência original