<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head> <body> <script> //使用settimeout new Promise((resolve, reject) => { setTimeout(() => { resolve('aaa') }, 1000) }).then(res => { console.log(res, '第一层的处理十个代码') return new Promise((resolve, reject) => { setTimeout(() => { resolve(res + '111') }, 1000) }) }).then(res => { console.log(res + '222') }) </script> </body> </html>
运行结果
