Functional testing

- [Instructor] Functional testing … is when we test the functionality of a system. … We're trying to see what it does, … or what things it's supposed to do … that it does not do. … Functional testing is probably … what we intuitively think of when we think of testing. … We're trying to see if the software … does what it's supposed to do. … Does my word processor let me type? … Can I make a word bold using the bold tool? … Does the indent tool properly indent my words? … These are all examples of functional tests. … At its heart, functional testing … is about how software changes things. … I give it some inputs, for example, … I highlight some text and type control B. … And the software does some work … and produces a certain output. … In this case, bolded text. … I find it helpful actually to go back … to my grade school math concepts … when I was introduced to mathematical functions. … We can think of it as a black box … where it takes in some inputs, … and then the function does something …