// 实现暂停功能
function sleep(time){
    let start = Date.now();
    let i = 0;
    while(true){
        let currentTime = Date.now();
        if(currentTime - start >= time){
            break;
        }
    }
}
// console.log(Date.now());
// sleep(2000);
// console.log(Date.now());

function sleep1(time,callback){
    setTimeout(callback,time)
}

// console.log(Date.now());
// sleep1(2000,function(){
//     console.log(Date.now());
// })
function sleep2(time){
    return new Promise((resovle)=>{
        setTimeout(resovle,time);
    });
}
// console.log(Date.now());
sleep2(2000).then(()=>{
    sleep2(2000).then(()=>{
        console.log(Date.now());
    })
})

async function test(){
    console.log(Date.now());
    await sleep2(2000);
    await sleep2(2000);
    console.log(Date.now());
}
test();