浏览器对象模型，提供了独立于内容和浏览器窗口进行交互的对象
// navigator
const ua = navigator.userAgent
const isChorme = ua.indexOf('Chrome')
console.log(isChrome)// screen
console.log(screen.width)
console.log(screen.height)// location
console.log(location.href)
console.log(location.protocol) // 协议
console.log(location.host)
console.log(location.search) // 传递的参数
console.log(location.hash)
console.log(location.pathname)