30-seconds-of-code/snippets/invertKeyValues.md

invertKeyValues

Inverts the key-value pairs of an object, without mutating it.

Use Object.keys() and Array.reduce() to invert the key-value pairs of an object.

const invertKeyValues = obj =>
  Object.keys(obj).reduce((acc, key) => {
    acc[obj[key]] = key;
    return acc;
  }, {});

invertKeyValues({ name: 'John', age: 20 }); // { 20: 'age', John: 'name' }