关于javascript:修改数组对象的属性名只修改对象的key不修改value

let arr = [ { name: '张三', year: 18}, { name: '李四', year: 19}] let brr = [ { userName: '张三', age: 18}, { userName: '李四', age: 19} ]changeKeys (arr, key) {  let newArr = [];  arr.forEach(item => {    let obj = {};    for (var i = 0; i < key.length; i++) {      obj[key[i]] = item[Object.keys(item)[i]]    }    newArr.push(obj);  })  return newArr;} let brr= changeKeys (arr, ['userName', 'age']);