Android™ How to Program, Second Edition

Declaring and Creating a Scanner to Obtain User Input from the Keyboard

A variable is a location in the computer’s memory where a value can be stored for use later in a program. All Java variables must be declared with a name and a type before they can be used. A variable’s name enables the program to access the value of the variable in memory. A variable’s name can be any valid identifier. A variable’s type specifies what kind of information is stored at that location in memory. Like other statements, declaration statements end with a semicolon (;).

Line 11 is a variable declaration statement that specifies the name (input) and type (Scanner) of a variable that’s used in this program. A Scanner enables a program to read data (e.g., numbers and ...