現有如下結構陣列，要求將具有相同lesson_id和number的物件合併，並更加lang欄位動態新增cname、ename鍵值

newData = [
{
"lesson_id": 56,
"lesson_name": "Adopt a Coaching Mindset",
"lang": 1,
"number": 1
},
{
"lesson_id": 56,
"lesson_name": "採用輔導式思維",
"lang": 2,
"number": 1
},
{
"lesson_id": 205,
"lesson_name": "Build a Coaching Habit",
"lang"
 
: 1,
"number": 2
},
{
"lesson_id": 205,
"lesson_name": "培養輔導習慣",
"lang": 2,
"number": 2
}
]

// 以number為標識，如果沒有那麼在定義的物件中建立它
let newObj = {}
newData.forEach(function (element) {
   if (typeof newObj[element.number] === 'undefined') {
      newObj[element.number] = {
      id: element.lesson_id,
      cname: ''
 
,
      ename: '',
      number: element.number
    }
  }
newObj[element.number][element.lang === 1 ? 'ename' : 'cname'] = element.lesson_name
}, this)

// 刪除空資料
for (let i = 0; i < newObj.length; i++) {
   if (newObj[i] === '' || typeof (newObj[i]) === 'undefined') {
      newObj.splice(i, 1)
      i = i - 1
 

   }
}

// 提取有用資料儲存為陣列
let arr1 = []
for (let item in newObj) {
  let obj1 = {
    id: newObj[item].id,
    cname: newObj[item].cname,
    ename: newObj[item].ename
 }
   arr1.push(obj1)
}
return arr1