ES6的Promise

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//实例化Promise对象          const p = new Promise(function(resolve, reject) {                setTimeout(() => {                    //    let data="数据库中的数据";                    //    resolve(data);                      let err = "数据读取失败";                    reject(err);                }, 1000);            })            //调用Promist对象中的then方法        p.then(            function(value) {                //  console.log(value);            },            function(reson) {                console.error(reson);            }        )