The json()
method of the Response
interface takes a Response
stream and reads it to completion. It returns a promise which resolves with the result of parsing the body text as JSON
.
Note that despite the method being named json()
, the result is not JSON but is instead the result of taking JSON as input and parsing it to produce a JavaScript object.
A Promise
that resolves to a JavaScript object. This object could be anything that can be represented by JSON — an object, an array, a string, a number...
In our fetch JSON example (run fetch JSON live), we create a new request using the Request()
constructor, then use it to fetch a .json
file. When the fetch is successful, we read and parse the data using json()
, then read values out of the resulting objects as you'd expect and insert them into list items to display our product data.
const myList = document.querySelector('ul');
const myRequest = new Request('products.json');
fetch(myRequest)
.then(response => response.json())
.then(data => {
for (const product of data.products) {
let listItem = document.createElement('li');
listItem.appendChild(
document.createElement('strong')
).textContent = product.Name;
listItem.append(
` can be found in ${
product.Location
}. Cost: `
);
listItem.appendChild(
document.createElement('strong')
).textContent = `£${product.Price}`;
myList.appendChild(listItem);
}
})
.catch(console.error);