Smaller C

Chapter 3. Flow of Control

Now that you have seen the basic format of a statement in C, it’s time to start branching out…pun intended. In code, the idea of making decisions and then selecting a particular bit of code to run instead of some other bit of code is often referred to as branching or conditional branching. And repetition is often discussed in terms of looping or iterating. Collectively, branching and looping statements comprise the flow of control in a language.

Some problems can be solved with a simple series of linear steps. Many programs that automate various computer tasks work just this way, taking a tedious routine and reducing that to a single app you can run whenever you need it. But programs can do much more than just process a batch of commands. They can make decisions based on the values in a variable or the state of a sensor. They can repeat tasks like turn on every LED in a string of lights or process every line in a log file. And they can combine the decision-making and repetition in complex, nested ways that allow you as the programmer to solve just about any problem you can think of. In this chapter we’ll look at how C implements these concepts.

Boolean Values

To ask a question in C, you typically compare two (or more) things. C has several operators meant for just this task. You can check to see if two things are the same. You can check to see if two things are not the same. You can see if some value is less than or greater than some other value.