promise 同步

方法

        //未执行
        function tes(params) {
            return new Promise((resolve, reject) => {
                console.log(444);
                setTimeout(() => {
                    resolve('fffh');
                }, 1000);
            })
        }
        tes().then((data) => {
            console.log(999, data)
            return 777;
        }).then((res) => {
            console.log(96, res)
        })

变量

        //已执行，但是只执行一遍
        var tes1 = new Promise((resolve, reject) => {
            console.log(666);
            setTimeout(() => {
                console.log(333);
                resolve('ccce');
            }, 1000);
        })
        tes1.then((data) => {
            console.log(999, data)
            return 777;
        }).then((res) => {
            console.log(96, res)
        })