basic-promises.js

//Promises - Just the Basic Facts
//wrappers for anything async
// ajax calls, reading files, timeouts, geolocation, talk to a database, or anything that would use a callback function
//use them to get rid of callback hell
//fetch() returns a Promise.

//var result = multiplyTwoNumbers(5, 10);
//console.log(result); //50
//
//var photo = downloadPhoto('http://localhost/cat.jpg');
// photo would be 'undefined'

const rand = () => Math.floor(Math.random() * 10) + 1;

let p1 = new Promise((resolve, reject) => {
    let x = 5;
    //resolve(x);  //calling this will call then()
    //reject(x);
    let num = rand();
    setTimeout(resolve, 1500, num)
})

//fetch().then().then().catch()



p1.then((ex) => {
    console.log(ex);
    return ex * 2;
}).then( (x) => {
    console.log(x);
}).catch( (exx) => {
    console.log('caught', exx);
})