实现一个 sleep 函数 #前端面试

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);