在 Javascript 对象中重命名所有属性名称的最快方法是什么？

Question

Say, I have an object that looks like this:

const a = {
  prop1: "val1",
  prop2: "val2",
  prop3: "val3",
  prop4: "val4",
}

And I want something like this derived from a :

const b = {
   something_prop1: "val1",
   something_prop2: "val2",
   something_prop3: "val3",
   something_prop4: "val4",
}

Is there any way to achieve this without having to create an intervening array of keys or running a for or foreach loop?

Answer 1

You could map new objects and build a single object with Object.assign and spread syntax ... .

 const a = { prop1: "val1", prop2: "val2", prop3: "val3", prop4: "val4" }, b = Object.assign(...Object.entries(a).map(([k, v]) => ({ ['something_' + k]: v }))); console.log(b);

Answer 2

You can do:

 const a = { prop1: "val1", prop2: "val2", prop3: "val3", prop4: "val4", }; const b = {}; Object.keys(a).forEach(k => b[`something_${k}`] = a[k]); console.log(b);

Answer 3

Here is an example with reduce if your point is not to use for or forEach .

 const a = { prop1: "val1", prop2: "val2", prop3: "val3", prop4: "val4", } const transformKeys = obj => Object.keys(obj).reduce((acc, key) => (acc[`something_${key}`] = obj[key], acc), {}); const b = transformKeys(a); console.log(b);