fetch.js

/*
 * Fetch API
 * https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API
 */

const uri = 'https://api.spotify.com/v1/albums/21KIagsx1ZvYcv0sVkEAWv/tracks';

const req = new Request(uri, {
	method: 'get',
	headers: new Headers({
    'content-type':'application/json'
  })
});

fetch(req)
	.then(res => {
		if(res.ok) {
			return res.json()
		} else {
			return Promise.reject({
				status: res.status,
				statusText: res.statusText
			})
		}
	})
	.then(data => {
		const obj = data.items;
		obj.forEach(function(i) {
			console.log(i);		
		});
	})
  .catch(err => {
  	console.log(err.statusText);
  });