javascript判断是电脑还是手机，android手机还是ios

function IsPC() {var userAgentInfo = navigator.userAgent;var Agents = ["Android", "iPhone","SymbianOS", "Windows Phone","iPad", "iPod"];var flag = true;for (var v = 0; v < Agents.length; v++) {if (userAgentInfo.indexOf(Agents[v]) > 0) {flag = false;break;}}return flag;}if(IsPC()){  //此处是电脑要执行的操作}else{  //此处是手机要执行的操作}

var ua = navigator.userAgent.toLowerCase();        var isWeixin = ua.indexOf('micromessenger') != -1;if (!isWeixin) {          alert('非微信')        }