1.8 What is output? What is output formatting? What are escape sequences?

A. Introduction:

How do you know if a program runs correctly or not? You check the results, or the output of the program. Sometimes the output is data, sometimes the output is a pattern like a Christmas tree. When printing out data values, you might want to generate the output in a certain format. For instance, dollar values should always have 2 decimal places, $2 should be $2.00.

B. System.out.println(), System.out.print() and System.out.printf()

1. We know System.out.println() prints strings, values of expressions, or both.

2. System.out.print() is similar, but always prints on the same line

3. System.out.printf() allows you to "format" the output such as the number of decimal places. For instance, System.out.printf("%.2f", Math.PI) prints Pi value with two decimal places.

4. How to use System.out.printf() ?

C. Try:

1. Did you print out a Christmas tree? Can you print a star on the tree top?

2. How to print out a dollar amount with leading $ and two decimal places?

3. How to print out two decimal values that are right aligned? For example,

4. Write a program that prints an animal speaking a greeting, similar to but different from the following. Notice to print '\', you need to enter '\\'. Learn more about escape sequences here.

 /\_/\     ----- 
( ' ' )  / Hello \
(  -  ) <  Junior |
 | | |   \ Coder!/
(__|__)    -----