Javascript 获取 api : Can't retrieve some response header

Question

我正在使用 javascript fetch API 来查询跨域 api，使用此代码:

fetch('https://api.com/search?query="2016"').then(function (response) {

  console.log(response.headers.get('Access-Control-Allow-Headers'))

  console.log(response.headers.get('Content-Range'))
  console.log(response.headers.get('Accept-Range'))

  console.log(response.headers.get('Date'))
  console.log(response.headers.get('Content-Type'))
})

响应头如下:

Accept-Range:cars 300
Access-Control-Allow-Credentials:true
Access-Control-Allow-Headers:Origin, X-Requested-With, Content-Type, Accept, Content-Range, Accept-Range
Access-Control-Allow-Methods:PUT, POST, OPTIONS, GET
Access-Control-Allow-Origin:*
Cache-Control:no-cache
Connection:keep-alive
Content-Range:0-99/1941
Content-Type:application/json
Date:Tue, 12 Jan 2016 12:17:55 GMT
Transfer-Encoding:chunked

非常奇怪的是，只有“Content-Type”对我得到的其他人有效 null :

null
null
null
null
application/json

我需要做什么来检索那些 null header ？

Answer 1

该死的，我使用的是“Access-Control-Allow-Headers”而不是“Access-Control-Expose-Headers”

现在可以了