Sequences, selections, and loops
Behind all of the software we use on a daily basis, there's a code being run with all sorts of terms and symbols. Surprisingly, it can often be broken down into three simple programming structures called sequences, selections, and loops. These come together to form the most basic instructions and algorithms for all types of software.
A sequence is a series of actions that
is completed in a specific order. Action 1 is performed, then
Action 2, then Action 3, etc., until all of the actions in the sequence have
been carried out.
A sequence we do every day is a morning routine.
You might wake up, drink some water, take a shower, eat breakfast, and so on.
Everyone's routine is different, but they're all made up of a sequence
of various actions.
Selections are a bit different. Instead of
following a specific order of events, they ask a question in
order to figure out which path to take next.
Let's say you go to brush your teeth, and you find that
you're out of toothpaste. You'd then ask, "Do I have any more
toothpaste?" If the answer is no, then you would add
it to your shopping list. But if the answer is yes, you would
just use the toothpaste. This is really all a selection is
doing: answering a question based on what it finds.
The third programming structure is a loop. Like
selections, loops ask questions. However, the difference is that they ask
the same question over and over and over again, until a certain
task is complete.
For example, take the act of hammering a nail. Even though
you may not realize it, you're constantly asking yourself, "Is the nail
all the way in?" When the answer is no, you hammer the
nail again. You continue to repeat this question until the answer is yes,
and then you stop. Loops allow programmers to efficiently code
repetitive tasks instead of having to write the same actions over and over
again.
These three programming structures may seem pretty simple on
their own, but when combined they can create some pretty complex software.
