前端2
<h4>题目1.如何实现sleep的效果（es5或者es6）</h4>
<p><strong>(1)通过Promise来实现</strong></p>
<pre><code class="language-javascript">function sleep(ms){
var temple = new Promise((resolve)=>{
console.log(111);
setTimeout(resolve,ms)
});
return temple
}
sleep(500).then(function(){
console.log(222)
})
//先输出111，延时500ms后输出222</code></pre>
<p><strong>(2) 通过async封装</strong></p>
<pre><code class="language-javascript">function sleep(ms){
return new Promise((resolve)=>setTimeout(resolve,ms));
}
async function test(){
var temple = await sleep(1000);
console.log(111)
return temple
}
text();//延迟1000ms输出1111</code></pre>