答案见控制台

    
      async function async1() {
        console.log('async1 start: ');
        await async2();
        console.log('async1 end');
      }

      async function async2() {
        console.log('async2');
      }

      console.log('script start');
      setTimeout(function() {
        console.log('setTimeout');
      }, 0)

      async1();

      new Promise(function(resolve) {
        console.log('promise executor');
        resolve();
      }).then(function() {
        console.log('promise resolved');
      });

      console.log('script end');
    
  

• 定时器、事件绑定是宏任务
• Promise、async和await是微任务
• 微任务跟在当前宏任务后面，执行完当前宏任务，立即其微任务，然后再执行下一个宏任务。