Add Functionality to Existing Global Interfaces
In this exercise, we're going to modify something on the
Here we have a
window.makeGreeting = () => "Hello!";
The function currently returns
"Hello!", but it needs to be updated to return any
As seen in the tests,
0:00 In this exercise, we're going to modify something on the window interface. We've got this window.makeGreeting is this function that returns hello. We just want it to basically represent type of window.makeGreeting. It should be just a function that returns a string. That's what we want.
0:18 We don't want it to be available on the global this. We just want it to be available on the window. How on earth do we type this? We're going to need declare global again. Then you're going to somehow need to modify the upper-case window interface to add a makeGreeting function.
0:37 You'll need to know some concepts of this. The first one is going to be declaration merging, which is something we haven't covered yet. There are some docs on it. I'll provide a link in the section resources. You might be able to just figure it out on your own because I've given you enough breadcrumbs here I think.
0:56 This looks complicated. Make sure that you're targeting the right interface using declare global. Good luck.