Compare Array of Objects in Javascript

Question

I'd like to make this array:

[
   {main: "material", value: "blend"}, 
   {main: "material", value: "synthetic"}, 
   {main: "style", value: "curl"}, 
   {main: "style", value: "bob"}, 
   {main: "material", value: "premium"}
]

to this:

{
 material: ["blend", "synthetic", "premium"], 
 style: ["curl", "bob"]
}

I used two "for-loops" but it didn't work out well:( Quite newbie in Javascript🥲

Answer 1

You can use reduce to have that result

const data = [{
  main: "material",
  value: "blend"
}, {
  main: "material",
  value: "synthetic"
}, {
  main: "style",
  value: "curl"
}, {
  main: "style",
  value: "bob"
}, {
  main: "material",
  value: "premium"
}]

const finalResut = data.reduce((result, currentData) => {
  const {
    main,
    value
  } = currentData
  if (!result[main]) {
    result[main] = []
  }
  result[main].push(value)
  return result
}, {})

console.log(finalResut)

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