Using variables
That's enough theory. Let's see how we would use our variables and types. Remember that each primitive type needs a specific amount of real device memory. This is one of the reasons why the compiler needs to know what type a variable will be.
Variable declaration
We must first declare a variable and its type before we try to do anything with it. To declare a variable of type int with the name unreadMessages, we would type the following:
int unreadMessages;
That's it—simply state the type (in this case, int), then leave a space and type the name you want to use for this variable. Note also that the ; semicolon at the end of the line will tell the compiler that we are done with this line and that what follows, if anything, is not part of the variable declaration.
Similarly, for almost all the other variable types, the declaration would occur in the same way. Here are some examples. The variable names in the examples are arbitrary....