Abstraction
abstraction is the process of ignoring minutiae and focusing on the big picture
nin modern life, we are constantly confronted with complexity
nwe don't necessarily know how it works, but we know how to use it
n
n e.g., how does a TV work?  a car?  a computer?
we survive in the face of complexity by abstracting away details
nto use a TV/car/computer, it's not important to understand the inner workings
nwe ignore unimportant details and focus on those features relevant to using it
n
ne.g., TV has power switch, volume control, channel changer, …
JavaScript functions (alert(), parseInt()) provide computational abstraction
na function encapsulates some “function” & hides the details from the user
nthe user needs to know only how to call the function, not how it works
nnote the ()
nthese functions have been predefined.
nin order to create our own abstractions, we must learn how functions work