js简化判断是否为手机访问

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
    }