Polling for a condition

- There will be times…when you need a program to detect…that some event has occurred,…and then react to that event…by performing a certain action.…To accomplish that, there are two approaches you could use:…polling, or event-driven programming.…With the polling method,…a program is continuously checking and checking and checking…and actively checking for a certain condition to occur,…like a button being pressed.…And when it sees that the condition has occurred,…it'll then perform an appropriate action.…My house is ready for my friends,…so now I'm just waiting…for the pizza delivery guy to get here.…

When the pizza man arrives,…I'll need to perform the appropriate action…by opening the door, and getting the pizza.…So, how will I know when the pizza man…is on the front porch to get my pizza?…Well, I could try the polling method,…and to do that, I'll have to get up off my bed,…then I go down the stairs,…(door opens) I check to see if he's here.…Not yet.…(door closes)…So then I head back up the stairs,…and then I return back to lounging.…