In a simple computer program, we like to imagine the flow of execution starting at the top and moving down line by line until it reaches the bottom. Sure, it might skip some lines if a condition for executing them is not met, or it might run some lines several times if there is an instruction to loop, but there shouldn’t be any reason for, say, a four line script to execute lines in an unexpected way. Indeed, PHP does execute code in the expected way, but as long as you have spent a bit of time thinking about what the “expected” way should be. To save you the trouble of having to think about this after writing some code which doesn’t work, and wondering why it doesn’t work, I will present an example of how PHP treats “jumping” in a four line script, and what that I mean by that term. Hopefully anyone who reads this will then want to avoid jumps in their code, as they will consider the practice harmful to the goal of writing maintainable software.
