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

    Simple demonstration of console output using:
    - System.out.print:   displays String with no linefeed
    - System.out.println: displays String and then a linefeed
    - System.out.printf:  formats output for display
*/

public class SimpleOutput {
    public static void main(String[] args) {
        // Declare and initialize variables
        int m = 3, n = 4;      // Multiple variables of the same data type
                               // can be declared and initialized together
        double pi = 3.1415926;
        String msg = "abcdefg";  // Note: String values are delimited using quotes
        
        // System.out.println does not require an argument
        System.out.println();  // displays nothing and goes to a new line

        // But normally, print/println have one argument. That's what they will display.
        
        // Display: Test output... abcdefg
        System.out.print("Test output... ");  // displays string with no line feed at end
        System.out.println(msg);     // displays value of variable with linefeed at end
        
        // Numbers can be displayed easily
        // Note: System.out.print/println converts them to Strings first
        System.out.println(9);   // displays: 9
        System.out.println(m);   // displays: 3
        System.out.println(n);   // displays: 4
        
        // Multiple items can be displayed by concatenating them into one String
        System.out.println("Hi" + "there");       // displays: Hithere
        System.out.println("m = " + m);           // displays: m = 3
        System.out.println("m + n = " + (m + n)); // displays: m + n = 7
        System.out.println("m + n = " + m + n);   // displays: m + n = 34
        // Note: The + sign can mean either addition of numbers or concatenation of
        // Strings. On the last println, Java chose concatenation because it was
        // evaluating the expression from left to right and it did not know how
        // to add m to the String, so it turned m into a String and concatenated the
        // two Strings. Then it did the same to n.
        
        // \n can be used to put a newline in a String
        // \r can be used to put a carriage return in a String
        System.out.println("a\nb\nc");  // displays a, b, c on separate lines
        
        // Many values can be concatenated for display
        System.out.println("The sum of " + m + " and " + n + " is " + (m+n));
        // Note the parentheses around m+n at the end so it gets calculated
        // before everything gets concatenated.
        
        // System.out.printf is used to format output
        System.out.println("The value of Pi is " + pi);      // displays: The value of Pi is 3.1415926
        System.out.printf("The value of Pi is %6.2f\n", pi); // displays: The value of Pi is   3.14
        System.out.printf("The value of Pi is %.2f\n", pi);  // displays: The value of Pi is 3.14
        
        // Note that System.out.printf has one or more arguments.
        // The first argument describes what will be displayed and the format.
        // The list of arguments after that provide the values for any conversion
        // specifiers in that first String. The conversion specifiers above are:
        //  %6.2f = field has width of six, two decimal positions, floating-point number
        //  %.2f = field width not specified, two decimal positions, floating-point number
        
        // You will usually have one extra argument for each conversion
        // specifier in the format String.
        System.out.printf("The value of m is %d, the value of n is %d\n", m, n);
        // Displays: The value of m is 3, the value of n is 4
    }
}