js fetch parameters code example

Example 1: fetch and then javascript send parameters

const url = 'https://randomuser.me/api';
// The data we are going to send in our request
let data = {
    name: 'Sara'
}
// The parameters we are gonna pass to the fetch function
let fetchData = { 
    method: 'POST', 
    body: data,
    headers: new Headers()
}
fetch(url, fetchData)
.then(function() {
    // Handle response you get from the server
});

Example 2: how to use fetch() javascript

//Most API's will only allow you to fetch on their website.
//This means you couldn't run this code in the console on 
// google.com because:
// 		1. Google demands the fetch request be from https
// 		2. open-notify's API blocks the request outside of their website

fetch('http://api.open-notify.org/astros.json')
.then(function(response) {
  return response.json();
})
.then(function(json) {
  console.log(json)
});

// Here is another example. A method (function) that 
// grabs Game of Thrones books from an API ...

function fetchBooks() {
  return fetch('https://anapioficeandfire.com/api/books')
  .then(resp => resp.json())
  .then(json => renderBooks(json));
}

function renderBooks(json) {
  const main = document.querySelector('main')
  json.forEach(book => {
    const h2 = document.createElement('h2')
    h2.innerHTML = `<h2>${book.name}</h2>`
    main.appendChild(h2)
  })
}

document.addEventListener('DOMContentLoaded', function() {
  fetchBooks()
})

Example 3: .fetch method

fetch('http://example.com/data.json')
  .then(data => data);
  .catch(err => console.log(err));