VIM Adventures is an online game based on VIM’s keyboard shortcuts. It’s the “Zelda meets text editing” game. So come have some fun and learn some VIM!
Modern JavaScript Tutorial: simple, but detailed explanations with examples and tasks, including: closures, document and events, object oriented programming and more.
Note that the value of diameter is a regular function, whereas the value of perimeter is an arrow function.
With arrow functions, the this keyword refers to its current surrounding scope, unlike regular functions! This means that when we call perimeter, it doesn’t refer to the shape object, but to its surrounding scope (window for example).
There is no value radius on that object, which returns NaN.
