Async - Await -- Promise

var sleep = function(){
	return new Promise(function(res,rej){
	  setTimeout(()=>{
		 res('sleep.....'); 
      },3000);
	})
};

var delay = function(){
   return new Promise(function(res,rej){
		setTimeout(function(){
			//调用res函数返回数据
			res('delay.....');
		},1000);
   })
};
var run = async function(){
	/**
	 * 首先执行slepp函数等待sleep执行结束之后，才能继续执行delay函数
	 */
	let result = await sleep();
	console.log(result);
	
	let delaySource = await delay();
	console.log(delaySource);
};

run();