Loop inside objects

We can travel inside Arrays with map, forEach and reduce function. What if we want to travel inside objects. As you known as objects has key and value so we can use those one all in one or separately.

Object.keys, values, entries

For plain objects, the following methods are available:

Object.keys(obj) – returns an array of keys.
Object.values(obj) – returns an array of values.
Object.entries(obj) – returns an array of [key, value] pairs.

let prices = {
  banana: 1,
  orange: 2,
  meat: 4,
};

let doublePrices = Object.fromEntries(
  // convert prices to array, map each key/value pair into another pair
  // and then fromEntries gives back the object
  Object.entries(prices).map(entry => [entry[0], entry[1] * 2])
);

alert(doublePrices.meat); // 8

Training question: Kata 8kyu Pirates!! Are the Cannons ready!

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Source

• javascript.info/keys-values-entries