判断页面是在移动端还是PC端打开的

$(function () {

　　var curWwwPath = window.document.location.href;
　　var pathName = window.document.location.pathname;
　　var pos = curWwwPath.indexOf(pathName);
　　var localhostPaht = curWwwPath.substring(0, pos);
　　var host = window.location.host;
　　var sUserAgent= navigator.userAgent.toLowerCase();
　　var bIsIpad= sUserAgent.match(/ipad/i) == "ipad";
　　var bIsIphoneOs= sUserAgent.match(/iphone os/i) == "iphone os";
　　var bIsMidp= sUserAgent.match(/midp/i) == "midp";
　　var bIsUc7= sUserAgent.match(/rv:1.2.3.4/i) == "rv:1.2.3.4";
　　var bIsUc= sUserAgent.match(/ucweb/i) == "ucweb";
　　var bIsAndroid= sUserAgent.match(/android/i) == "android";
　　var bIsCE= sUserAgent.match(/windows ce/i) == "windows ce";
　　var bIsWM= sUserAgent.match(/windows mobile/i) == "windows mobile";

　　if (bIsIpad || bIsIphoneOs || bIsMidp || bIsUc7 || bIsUc || bIsAndroid || bIsCE || bIsWM) {
　　　　//mobile
　　　   if ((localhostPaht +"//"+host) != 'https://m.meiwo.cn'){
　　　　　    window.location.href = 'https://m.meiwo.cn';
　　　　}
　　  } else {
　　　　//pc
　　　   if ((localhostPaht +"//" +host) != 'https://www.meiwo.cn'){
　　　　　　    window.location.href = 'https://www.meiwo.cn';
　　　　}
　　}

})

window.location.href = /Android|webOS|iPhone|iPad|BlackBerry/i.test(navigator.userAgent) ? "https://www.baidu.com/" :  "http://news.baidu.com/";
或

if(/Android|webOS|iPhone|iPad|BlackBerry/i.test(navigator.userAgent)) {
    window.location.href = "https://www.baidu.com/";
} else {
    window.location.href = "http://news.baidu.com/";
}