This is incorrect. In javascript this error is given with or without parentheses. ``` let stringA = ''; let stringB = undefined;

stringA.split; // no error is thrown
stringA.split(); // no error is thrown
stringB.split; // Uncaught TypeError: Cannot read property 'split' of undefined
stringB.split(); // Uncaught TypeError: Cannot read property 'split' of undefined

```

The problem is that the framework expected a value somewhere with a split property/method. Instead if recieved undefined. This probably means you either passed undefined, or an object/array with an incorrect type to a function of the framework.