Now that we have some background on what types are, we can talk about what variables are and how we make and use them. A variable is a named value (like a constant) with the added feature that it can change during the running of a program. If we’re working with a value in various places in our program, we can store that value in a variable to easily access it later.
Variables are defined with the
var keyword and two pieces of information: the name that we will use to refer to them and the type of data stored in the variable. Since variables can be updated we don’t even need to assign a value initially. Here’s a couple of variable definitions:
var lengthOfSong uint16 var isMusicOver bool var songRating float32
Above, we created three variables:
- An unsigned 16-bit integer called
- A boolean value called
- A 32-bit float called
Notice that our variable names also follow the same naming convention of constants, using camelCase with a descriptive name.
Create a variable called
jellybeanCounter, that will store the number of jellybeans in a jar. Give it a type of
Successfully doing this will result in an error! We’ll talk more about errors in Go and how to read them in the next exercise, so continue when you’re ready.