基于单个属性从 javascript 中的两个 arrays 中删除重复项

Question

I have two arrays in javascript, where i want to do two different operations

1. Map an attribute upon each element in each lists
2. filter out none unique values based on an attribute

I have this function so far

export function generateDisplayedLabels(systemLabels, masterState){
  const mappedSystemlabels = systemLabels.map(label => Object.assign(label, {type: "system"}))
  const mappedMasterlabels = masterState.map(label => Object.assign(label, {type: "master"}))
  const displayedLabels = _.union(mappedSystemlabels, mappedMasterState);
  return displayedLabels

}

This would work except for the fact, that whenever i map over the objects in the beginning, the "unique" elements are no longer unique, because they have another attribute mapped upon it. Is there a time efficient way, that i can filter out the none unique elements, ignoring the attribute, that have been mapped onto it.

Answer 1

 let ar1 = [ { id: 1, name: 'stack', }, { id: 2, name: 'react', }, ]; let ar2 = [ { id: 1, name: 'javascript', }, { id: 2, name: 'overflow', }, { id: 2, name: 'react', }, ]; console.log(_.unionBy(ar1, ar2, 'id')); console.log("======"); console.log(_.unionBy(ar1, ar2, 'name'));

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