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Plucking properties from object arrays


One of the more common tasks when mapping over arrays in JavaScript is extracting properties from objects. Instead of using individual arrow functions, we can create a reusable helper function that does the plucking for us.

const countries = [
  { name: 'France', capital: 'Paris'  },
  { name: 'Spain',  capital: 'Madrid' },
  { name: 'Italy',  capital: 'Rome'   }

// we can extract the attributes with individual arrow functions =>     // ⇒ ['France', 'Spain', 'Italy'] =>  // ⇒ ['Paris', 'Madrid', 'Rome']

// this function allows us to write that arrow function shorter
const pluck = property => element => element[property]'name'))     // ⇒ ['France', 'Spain', 'Italy']'capital'))  // ⇒ ['Paris', 'Madrid', 'Rome']