Promise、async、await

// 新建Promise
function getTime(timeout) {
    return new Promise((resolve, reject)=>{
        var now = new Date()
        setTimeout(() => {
            if(timeout) {
                resolve(now)
            }else {
                reject(now)
            }
        }, timeout);
    })
}

// Promise执行方式1
getTime(2000).then((data)=>{
    console.log('success:'+data)
    console.log(new Date())
},()=>{
    console.log('failed:'+data)
})

// Promise执行方式2
getTime(2000).then((data)=>{
    console.log(data)
    console.log(new Date())
}).then((data)=>{
    console.log(data)
})

// async、await执行
async function printTime(params) {
    var time = await getTime(params)
    console.log(time)
    console.log(new Date())
}
printTime(2000)