var beginTime = 0；//执行onbeforeunload的开始时间
var differTime = 0;//时间差
window.onunload = function (){
differTime = new Date().getTime() - beginTime;
if(differTime <= 5) {
console.log("浏览器关闭")
}else{
console.log("浏览器刷新")
}
}
window.onbeforeunload = function (){
beginTime = new Date().getTime();
};