30秒学会 JavaScript 片段 – mapKeys

Creates an object with keys generated by running the provided function for each key and the same values as the provided object.

Use Object.keys(obj) to iterate over the object’s keys.
Use Array.prototype.reduce() to create a new object with the same values and mapped keys using fn.

代码片段

const mapKeys = (obj, fn) =>
  Object.keys(obj).reduce((acc, k) => {
    acc[fn(obj[k], k, obj)] = obj[k];
    return acc;
  }, {});

使用样例

mapKeys({ a: 1, b: 2 }, (val, key) => key + val); // { a1: 1, b2: 2 }