js 获取浏览器内核

<script language="JavaScript" type="text/javascript">
    var browser = {
        versions: function () {
            var u = navigator.userAgent, app = navigator.appVersion;
            return {//移动终端浏览器版本信息
                trident: u.indexOf('Trident') > -1, //IE内核
                presto: u.indexOf('Presto') > -1, //opera内核
                webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核
                gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核
                mobile: !!u.match(/AppleWebKit.*Mobile.*/) || !!u.match(/AppleWebKit/), //是否为移动终端
                ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios终端
                android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android终端或者uc浏览器
                iPhone: u.indexOf('iPhone') > -1 || u.indexOf('Mac') > -1, //是否为iPhone或者QQHD浏览器
                iPad: u.indexOf('iPad') > -1, //是否iPad
                webApp: u.indexOf('Safari') == -1 //是否web应该程序，没有头部与底部
            };
        } (),
        language: (navigator.browserLanguage || navigator.language).toLowerCase()
    }
  document.writeln("内核: " + browser.versions.trident);//可修改
    document.writeln("语言版本: " + browser.language);
    document.writeln(" 是否为移动终端: " + browser.versions.mobile);
    document.writeln(" ios终端: " + browser.versions.ios);
    document.writeln(" android终端: " + browser.versions.android);
    document.writeln(" 是否为iPhone: " + browser.versions.iPhone);
    document.writeln(" 是否iPad: " + browser.versions.iPad);
    document.writeln(navigator.userAgent);
</script>