His example has at least 2 missing semicolons.<p>function Logger() { }<p>// Log something to the console at a specified level<p>Logger.prototype.log = function(level) {<p><pre><code> console[level || 'log'].apply(console,[].slice.apply(arguments, 1));
</code></pre>
}; // here<p>// Sugar functions for Logger.log<p>['info', 'warn', 'error'].forEach(function(level) {<p><pre><code> Logger.prototype[level] = function () {
return this.log.apply(this, [level].concat(Array.from(arguments)));
}; // here
</code></pre>
});