/*
    Variables2.java
    CIS 160
    David Klick
    2015-09-02

    Demonstration of using variables.
*/

public class Variables2 {
    public static void main(String[] args) {
        // Variables are named memory locations that store data.
        // We have to specify a name and data type to create a variable.
        // We have to declare a variable before we use it.
        // We have to initialize a variable before we try to use its value.
        
        // Declare a variable
        double sum;      // this variable is not initialized
        
        // Declare and initialize variables
        double x;
        x = 3.4;
        double y = 8.9;  // you can initialize at the same time you declare
        
        // Do some simple math
        //    In this case x and y had to be initialized because we are using their values.
        //    sum did not have to be initialized because we are setting its value.
        //    The = is the assignment operator. Java calculates the value on the right
        //    side of the = and stores the value in the variable on the left side.
        sum = x + y;
        
        // Display the result
        //    System.out.println() is a method used to send something to the display.
        //    You should see 12.3 when you run this program.
        System.out.println(sum);
    }
}