JavaScript fetch API - Why does response.json() return a promise object (instead of JSON)? [duplicate]

I've just started to learn the Fetch API:

Here's a code snippet which I wrote to tinker around with it:

fetch(') .then(function(response) { var json = response.json(); console.log(json); // Expected : { "name": "Luke Skywalker","height": "1.72 m", ... } // Get : Promise {[[PromiseStatus]]: "pending", [[PromiseValue]]: undefined} }); 

I would have expected to get an JSON object out of response.json().

Similar to what you get when using JSON.parse().

Instead I get a promise object.

If I enlarge the promise chain like shown here ...

return response.json().then(function(json) { // process your JSON further }); 

... then it works: Within the then method of the following promise it appears as json.

Why can't I retrieve the JSON data within the then() of the first promise?

Can anyone please explain what is going on here?

I would really much appreciate it.

1 Answer

because response.json() returns another promise (which is within your function body)