var ua = navigator.userAgent;
var ipad = ua.match(/(iPad).*OS\s([\d_]+)/),
isIphone = !ipad && ua.match(/(iPhone\sOS)\s([\d_]+)/),
isAndroid = ua.match(/(Android)\s+([\d.]+)/),
isMobile = isIphone || isAndroid;
if(isMobile) {
location.href = 'http://m.domain.com';
}else{
location.href = 'http://www.domain.com';
}
//或者单独判断iphone或android
if(isIphone){
//code
else if(isAndroid){
//code
}else{
//code
}