console.log(document.readyState);

//監聽，當readystate狀態改變就觸發(loading,interactive,complete)
document.onreadystatechange = function () {

  console.log(document.readyState); 

  if (document.readyState == "loading") {
    //這邊一定不會進來，因為網頁一開始狀態就是loading，沒有改變，也不會觸發onreadystatechange
    console.log('The document is still loading.');
  }
  if (document.readyState == "interactive") {
    console.log('The document has finished loading and the document has been parsed but sub-resources such as images, stylesheets and frames are still loading.');
  }
  if (document.readyState == "complete") {
      // document is ready. Do your stuff here
    console.log('The document and all sub-resources have finished loading. The state indicates that the load event is about to fire.');
  }
}

const asyncReadFile = async function () {
  const afile = await readFile('/etc/fstab');
  const bfile = await readFile('/etc/shells');
  console.log(afile.toString());
  console.log(bfile.toString());
};

class People {
  constructor(height, money) {
    this.height = height;
    this.money = money;
  }
  work() {
    console.log('I am working');
  }
  play() {
    console.log('I am playing');
  }
  //info 可以先不用看
  info() {
    console.log('我身高',this.height, '我有',this.money);
  }
}
//----------------特殊舉例-可以先不用理會-------------------
let cMan =new People ('0cm','0元');
//----------------aMan-object---------------------
class aMan extends People {
  swim() {
    console.log('aMan','I am swimming');
  }
};
//----------------new-aMan------------------------
let poolMan = new aMan('165cm', '5億');
//----------------bMan-object---------------------
class bMan extends People {
  constructor(height, money, face) {
    super(height, money);
    this.face = face;
  }
  swim() {
    console.log('bMan','I am swimming');
  }
  talk() {
    console.log('bMan','I am talking');
  }
  //info 可以先不用看
  info() {
    console.log('我身高有',this.height, '我錢有',this.money,'我臉很',this.face);
  }
};
//----------------new-bMan------------------------
let richMan = new bMan('195cm','500億','帥');

function() {
  return false;
}

// IS EQUAL TO

function(event) {
  event.preventDefault();
  event.stopPropagation();
}

document.addEventListener(event, function, useCapture)