isIOS9

function isIOS9() {
    //获取固件版本
    var getOsv = function () {
        var reg = /OS ((d+_?){2,3})s/;
        if (navigator.userAgent.match(/iPad/i) || navigator.platform.match(/iPad/i) || navigator.userAgent.match(/iP(hone|od)/i) || navigator.platform.match(/iP(hone|od)/i)) {
            var osv = reg.exec(navigator.userAgent);
            if (osv.length > 0) {
                return osv[0].replace('OS', '').replace('os', '').replace(/s+/g, '').replace(/_/g, '.');
            }
        }
        return '';
    };
    var osv = getOsv();
    var osvArr = osv.split('.');
    //初始化显示ios9引导
    if (osvArr && osvArr.length > 0) {
        if (parseInt(osvArr[0]) >= 9) {
           return true
        }
    }

    return false
}
原文地址:https://www.cnblogs.com/jzm17173/p/4962158.html