Learn React with TypeScript 3

Consuming a promised-based function

Let's have a quick look at some code that exposes a promise-based API:

fetch("https://jsonplaceholder.typicode.com/posts")  .then(response => response.json())   .then(data => console.log(data))  .catch(json => console.log("error", json));

• This function is the native JavaScript fetch function for interacting with RESTful APIs
• The function takes in a URL for the request
• It has a then method to handle the response and reading of the response body
• It has a catch method to handle any errors

The code execution flows down as we would read it. We also don't have to do any additional work in the then methods to handle errors. So, this is much nicer than working with callback-based asynchronous code.

In the next section ...