Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript Asynchronous Programming with JavaScript Understanding Promises JavaScript Promises Review

Danny L.
Danny L.
10,837 Points
Posted by Danny L.
Danny L.
10,837 Points

Confused about .json() vs .text()

In the final quiz of the Promises section there was this question:

Complete the code by using the method that fetches resources across the network, and the method that parses a Response stream to JSON.

I got the answer correct but I'm just not sure why. I couldn't remember us using .json() anywhere. Why would we use .json() here instead of .responseText?

 fetch ('api.cooldogs.com')
   .then( res => res.json() )
   .then( json => console.log(json) )

1 Answer

Steven Parker
Steven Parker
231,186 Points
Steven Parker
Steven Parker
231,186 Points

The "fetch" result has no "responseText" property, so I assume you meant to say "res.text()"

In that case, the difference is that ".text()" will give you the result in string format, and ".json()" will parse it from JSON and convert it into an object.

But another issue with this example is that the domain "cooldogs.com" seems to no longer be a functioning service and currently belongs to one of those darn domain squatters. You might try the API at dog.ceo as an alternative.