pluck

Converts an array of objects into an array of values corresponding to the specified key.

• Use Array.prototype.map() to map the array of objects to the value of key for each one.

const pluck = (arr, key) => arr.map(i => i[key]);

const simpsons = [
  { name: 'lisa', age: 8 },
  { name: 'homer', age: 36 },
  { name: 'marge', age: 34 },
  { name: 'bart', age: 10 }
];
pluck(simpsons, 'age'); // [8, 36, 34, 10]