var _STRING = "string", _ARRAY = "array", _HELLO = "Hola", _SPACE = " ";

function toType(obj) {
    //return ({}).toString.call(obj).match(/\s([a-z|A-Z]+)/)[1].toLowerCase();

    //Expresión regular mejorada
    //return ({}).toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase();

    // Usando el "slice"
    return ({}).toString.call(obj).slice(8,-1).toLowerCase();
}

function isArray(input) {
    return toType(input) === _ARRAY;
}

function isString(input) {
    return toType(input) === _STRING;
}

function convertString(input) {
    (toType(input) === _STRING && (input = input.trim())) || (input = "");
    return input;
}

function getNamesFromArray(input) {
    var names = [],
        namesMaxLen = input.length,
        item,
        current;
    for (item = namesMaxLen; item > 0; --item) {
        current = input[namesMaxLen - item];
        if (isString(current)) {
            names.push(current);
        } else if (isArray(current)) {
            names = names.concat(getNamesFromArray(current));
        }
    }
    return names;
}

var crearSaludo = function(input) {
    var result,
        current,
        names,
        namesMaxLen,
        subNamesMaxLen,
        item,
        subItem,
        funcSaludo;
    var saludo = function() {
        current = convertString(input);
        if (current.length > 0) {
            result = _HELLO + _SPACE + current;
        }
        return result;
    };
    if (isArray(input)) {
        funcSaludo = [], names = [], namesMaxLen = input.length;
        for (item = namesMaxLen; item > 0; --item) {
            current = input[namesMaxLen - item];
            if (isString(current)) {
                funcSaludo.push(crearSaludo(current));
            } else if (isArray(current)) {
                names = getNamesFromArray(current);
                subNamesMaxLen = names.length;
                for (subItem = subNamesMaxLen; subItem > 0; --subItem) {
                    funcSaludo.push(crearSaludo(names[subNamesMaxLen - subItem]));
                }
            }
        }
    } else {
        funcSaludo = saludo;
    }
    return funcSaludo;
};