Returning from callbacks

callback_style.js

var fs = require('fs');

String.prototype.endsWith = function (suffix) {
    return this.indexOf(suffix, this.length - suffix.length) !== -1;
};

exports.ls1 = function ls1(dir, ext, callback) {
    try {
        fs.readdir(dir, function (err, files) {
            if (err) return callback(err, null);

            var filtered = files.filter(function (element) {
                return element.endsWith('.' + ext);
            });

            return callback(err, filtered);
        });
    }
    catch (err) {
        callback(err, null);
    }
};

// VERSUS

exports.ls2 = function ls2(dir, ext, callback) {
    try {
        fs.readdir(dir, function (err, files) {
            if (err) callback(err, null);

            var filtered = files.filter(function (element) {
                return element.endsWith('.' + ext);
            });

            callback(err, filtered);
        });
    }
    catch (err) {
        callback(err, null);
    }
};