Convert object key to array with values number of key with Lodash [duplicate]

Answer 1

With lodash you can iterate the array with _.flatMap(). Create the the callback using _.overArgs() that will pass the value (via _.identity()) and the key (wrapped with _.constant()) to _.times():

const obj = {
  products: {
    bread: 1,
    milk: 2,
    cheese: 2,
    chicken: 1,
  }
}

const result = _.flatMap(obj.products, _.overArgs(_.times, [_.identity, _.constant]))
  
console.log(result)

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Answer 2

You could use flatMap over the entries of the object

const products = {
  bread: 1,
  milk: 2,
  cheese: 2,
  chicken: 1,
}

const output = Object.entries(products).flatMap(([k, v]) => Array(v).fill(k))

console.log(output)