获取指定ua信息或者全ua信息

function getUA(OSArray) {
    var OSMap = {},
        UA = navigator.userAgent.toLowerCase(),
        EvalStr = '';
    //如果不传参或者传参不为数组或者为空数组，默认返回所有操作系统信息
    if (OSArray instanceof Array === false || OSArray.length < 1) {
        OSArray = UA.match(/(\S*)\/(\S*)/g);
        OSArray.forEach(function(v, i) {
            OSMap[OSArray[i].split('/')[0]] = OSArray[i].split('/')[1];
        })
    } else {
        OSArray.forEach(function(v, i) {
            if (UA.indexOf(v) > -1) {
                EvalStr = "UA.match((/(\\S*" + v + ")\\/(\\S*)/g) || [, '\'])[0]";
                OSMap[v] = eval(EvalStr).split('/')[1];
            } else {
                OSMap[v] = false;
            }
        })
    }
    return OSMap;
}
// var tr = ua.match(/(\S*mozilla)\/(\S*)/g)
var UaMyInfo = getUA(['applewebkit', 'safari', 'micromessenger']);
console.log(UaMyInfo);
var UaAllInfo = getUA();
console.log(UaAllInfo);