js判断是PC端还是手机端

第一种：简单实用的

<script type="application/javascript">
    var PC = IsPC();
    if (!PC) {
        location.href = "index_m.html";
    }

    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;
    }
</script>

第二种：

function browserRedirect() {  
    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) ){  
        window.location.href=B页面;  
    }  
}  
browserRedirect();  

第三种：百度的判断

function uaredirect(f) {  
 try {  
  if (document.getElementById("bdmark") != null) {  
   return  
  }  
  var b = false;  
  if (arguments[1]) {  
   var e = window.location.host;  
   var a = window.location.href;  
   if (isSubdomain(arguments[1], e) == 1) {  
    f = f + "/#m/" + a;  
    b = true  
   } else {  
    if (isSubdomain(arguments[1], e) == 2) {  
     f = f + "/#m/" + a;  
     b = true  
    } else {  
     f = a;  
     b = false  
    }  
   }  
  } else {  
   b = true  
  }  
  if (b) {  
   var c = window.location.hash;  
   if (!c.match("fromapp")) {  
    if ((navigator.userAgent.match(/(iPhone|iPod|Android|ios|SymbianOS)/i))) {  
     location.replace(f)  
    }  
   }  
  }  
 } catch(d) {}  
}  
function isSubdomain(c, d) {  
 this.getdomain = function(f) {  
  var e = f.indexOf("://");  
  if (e > 0) {  
   var h = f.substr(e + 3)  
  } else {  
   var h = f  
  }  
  var g = /^www\./;  
  if (g.test(h)) {  
   h = h.substr(4)  
  }  
  return h  
 };  
 if (c == d) {  
  return 1  
 } else {  
  var c = this.getdomain(c);  
  var b = this.getdomain(d);  
  if (c == b) {  
   return 1  
  } else {  
   c = c.replace(".", "\\.");  
   var a = new RegExp("\\." + c + "$");  
   if (b.match(a)) {  
    return 2  
   } else {  
    return 0  
   }  
  }  
 }  
};