i399exback/promises.js

31 lines
632 B
JavaScript

var promise = Promise.resolve(1); // vs. Promise.reject(new Error('failed'));
promise.then(result => {
console.log('1: ' + result);
return getData(result);
}).then(result => {
console.log('2: ' + result);
return 1;
}).then(result => {
// no return
}).then(result => {
throw new Error('sth bad happened');
}).then(result => {
// skipped
}).catch(error => {
// process error
// throw error
// return 1
}).then(result => {
// executed if catch
// does not throw
});
function getData() {
return Promise.resolve('some data');
// return Promise.reject(new Error('no data'));
}