<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <script> console.log(typeof Promise); console.dir(Promise); var p = new Promise(function(resolve, reject) { //这里实现一步任务 setTimeout(function() { var flag = true; if (flag) { //正常情况 resolve('hello'); } else { reject('出错了'); } }, 100) }); p.then(function(data) { console.log(data) }, function(info) { console.log(info); }) </script> </body> </html>
