js实现sleep函数

四种方式：

//Promise
const sleep = time => {
return new Promise(resolve => setTimeout(resolve,time))
}
sleep(1000).then(()=>{
console.log(1)
})

//Generator
function* sleepGenerator(time) {
yield new Promise(function(resolve,reject){
setTimeout(resolve,time);
})
}
sleepGenerator(1000).next().value.then(()=>{console.log(1)})

//async
function sleep(time) {
return new Promise(resolve => setTimeout(resolve,time))
}
async function output() {
let out = await sleep(1000);
console.log(1);
return out;
}
output();

//ES5
function sleep(callback,time) {
if(typeof callback === 'function')
setTimeout(callback,time)
}

function output(){
console.log(1);
}
sleep(output,1000);