https://segmentfault.com/a/1190000017935821

  let girlName = "裘千尺"

  function hr(callBack) {
    setTimeout(() => {
      girlName = "黃蓉"
      console.log('我是黃蓉');
      callBack()
    }, 0);
  }

  function gj() {
    console.log(`${girlName}你好，我是郭靖，認(rèn)識一下吧`);
  }
  hr(gj)

//=>我是黃蓉
//=>黃蓉你好，我是郭靖，認(rèn)識一下吧