I have googled the syntax. However, I think the instruction should give an example for declare the return type function!!

Step 6

You will need a function to generate a range of numbers.

Declare an empty range function which takes a start and endparameter. Use the Array() constructor and implicitly return an empty array.

My ans:

const range = (start, end) => Array();

Hello, Upon reading the instructions an empty range function, I assume is a function without a block, so you have a point if there is no mention of this type.

Arrow functions with implicit returns were introduced with an example in a previous Step.