ua判断

tencent-detectua-function.js

 function detectua(ua) {
        var os = {},
            browser = {},
            android = ua.match(/([a|A]ndroid)[\s\/]*([\d.]+)/),
            ipad = ua.match(/(iPad).*OS\s([\d_]+)/),
            iphone = !ipad && ua.match(/(iPhone\sOS)\s([\d_]+)/),
            wechat = ua.match(/MicroMessenger\/([\d\.]+)/),
            qqbrowser = ua.match(/MQQBrowser\/([\d\.]+)/);
        if (/android/i.test(ua)) {
            os.android = true;
            if (android) {
                os.version = android[2];
            }
        }
        if (/(iPhone|iPad|iPod|iOS)/g.test(ua)) {
            os.ios = true;
            if (iphone) {
                os.iphone = true, os.version = iphone[2].replace(/_/g, ".");
            }
            if (ipad) {
                os.ipad = true, os.version = ipad[2].replace(/_/g, ".");
            }
        }
        if (wechat) {
            browser.wechat = true, browser.version = wechat[1];
        }
        if (qqbrowser) {
            browser.qqbrowser = true, browser.version = qqbrowser[1];
        }
        return {
            os: os,
            browser: browser
        };
    }

good