ES8 async并发执行

    {
            let task1 = () => new Promise((resolve, reject) => {
                console.log("task1 begin")
                setTimeout(() => resolve("task1 end.返回结果"), 1000)
            })

            let task2 = () => new Promise((resolve, reject) => {
                console.log("task2 begin")
                setTimeout(() => resolve("task2 end.返回结果"), 1000)
            })


            async function fun() {
                // let result1 = await task1()
                // console.log(result1)
                // let result2 = await task2()
                // console.log(result2)
                // console.log("fun end")

                //并发执行
                let task1Promise = task1()
                let task2Promise = task2()

                let result1 = await task1Promise
                console.log(result1)

                let result2 = await task2Promise
                console.log(result2)
            }

            fun()
        }


        {
            //async function fun() { }

            //let fun = async function () { }

            //let fun = async () => { }

        }