写在前面：

在对数组或对象进行遍历时，我们经常会使用到两种方法: for in和for of，那么这两种方法之间的区别，我们今天直接使用例子来说明

被遍历的数组：

orderDocotorList[
{"DoctorId":"1","DoctorName":"测试","DoctorCode":"3","DoctorSkill":null,"DoctorDesc":null,"DoctorTitle":null,"DoctorSex":null,"LocationId":"1","LocationName":"内二科","LocationCode":"001","LocationRoom":"测试诊室","LocationRoomId":null},
{"DoctorId":"42","DoctorName":"孙继良","DoctorCode":"10042","DoctorSkill":null,"DoctorDesc":null,"DoctorTitle":null,"DoctorSex":null,"LocationId":"1","LocationName":"内二科","LocationCode":"001","LocationRoom":"心血管内科","LocationRoomId":null},
{"DoctorId":"42","DoctorName":"孙继良","DoctorCode":"10042","DoctorSkill":null,"DoctorDesc":null,"DoctorTitle":null,"DoctorSex":null,"LocationId":"1","LocationName":"内二科","LocationCode":"001","LocationRoom":"心血管内科","LocationRoomId":null}
]

两种遍历方法：

for in

   for (const doctorItem of this.orderDocotorList){
                console.log('遍历数组',doctorItem,doctorItem.DoctorId)
            }

输出结果：

for of

for (const index in this.orderDocotorList){
                console.log('遍历数组',index,index.DoctorId)
            }

输出结果：

结论：

for in遍历的是数组的索引（即键名），而for of遍历的是数组元素值

for in总是得到对象的key或数组、字符串的下标

for of总是得到对象的value或数组、字符串的值