# Summary

In this chapter, we got into the nitty-gritty of variables, including how variables are declared, and all the different notations you can use to declare them. This variety of notation gives you a nice compact notation to use for 90% of your work, while still giving you the power to be very specific when you need to the other 10% of the time. We looked at how to change and update the value of variables after you've declared them. Again, Go gives you some great shorthand to help in the most common use cases to make your life easier. All your data ends up in some form of variable. Data is what makes code dynamic and responsive. Without data, your code could only ever do exactly one thing; data unleashes the true power of software.

Now that your application has data, it needs to make choices based on that data. That's where variable comparison comes in. This helps us see whether something is true or false, bigger or smaller, and to make choices based on the results of those comparisons.

We explored how Go decided to implement their variable system by looking at zero values, pointers, and scope logic. Now, we know that these are the details that can be the difference between delivering bug-free efficient software and not doing so.

We also took a look at how we can declare immutable variables by using constants and how `iota`

can help manage lists or related constants to work, such as enums.

In the next chapter, we'll start to put our variables to work by defining logic and looping over collections of variables.