fetch请求返回的中间结果应该调用什么?一个blob还是只是响应?
当我们在 JS 中使用 fetch
发出 get 请求时,我们通常会这样做
when we use fetch
in JS to issue a get request, we normally do thing like this
fetch(endpoint).then(res => res.json()).then(result => ...)
但是,我正在观看 Wes Bos 的 JS 30 课程,他称中间结果为 fetch 返回一个 blob
,如
However I was watching Wes Bos's JS 30 courses and he called the intermediate result that the fetch returns a blob
as in
fetch(endpoint).then(blob => blob.json()).then(result => ...)
我在这里找到了 blob 的定义 https://developer.mozilla.org/en-US/docs/Web/API/Blob
I found the definition for blob here https://developer.mozilla.org/en-US/docs/Web/API/Blob
我没有足够的知识来判断 Wes Bos 是否在这里使用了正确的术语来将其称为 blob
,我无法直接联系他并询问他.希望我能在这里找到一些答案.
I am not knowledgable enough to judge if Wes Bos was using the right term here to refer to it as blob
and I have no ways to contact him directly and ask him. Hope I can find some answers here.
推荐答案
fetch
返回一个 Response
对象,而不是 Blob
- 如果您尝试使用像 .slice
和 .stream
结果会抛出错误,因为这些方法不存在.
fetch
returns a Response
object, not a Blob
- if you try to use blob methods like .slice
and .stream
on the result, errors will be thrown, since those methods do not exist.
// Not OK:
fetch('data:,Hello%2C%20World!').then(blob => blob.slice()).catch((err) => console.log('err', err.message));
// OK:
fetch('data:,Hello%2C%20World!').then(res => res.text()).then(console.log);
请注意,响应可以转换为 Blob,但 fetch
的返回值仍然是响应:
Note that the Response can be converted into a Blob, but the return value from fetch
would still be a Response:
fetch(endpoint)
.then(response => response.blob())
.then((blob) => {
// work with the blob here
});
将响应称为 blob 是不正确的.它们有些相似,但又不一样.最好避免将其称为 blob
以避免混淆.
Calling the response a blob is incorrect. They're somewhat similar, but not the same. Better to avoid calling it a blob
to avoid confusion.
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