Formatting Output

• System.out.println(String) prints the desired string to standard output (often the console window), and System.out.println(String) prints the String, followed by a new line.
• You can use the java.text.NumberFormat class to format numbers.
• NumberFormat.getNumberInstance() formats numbers with commas and decimals.
• NumberFormat.getCurrencyInstance() formats numbers for currnecy, with a dollar sign and two digits after the decimal.
• NumberFormat.getPercentInstance() formats numbers as a percentage, with the percent sign at the end.
• You can enter a locale in the get methods above to set the number instance for a specific country.  This will allow your Java program to use notation from other countries.
• Use the get methods mentioned above to create an object of the NumberFormat class.  Then, you can use that object as many times as you need to format multiple numbers.
• Use the format() method of the NumberFormat class to actually format the number.  This method returns a String object.
• Other handy methods:
• setMaximumFractionDigits() sets the maximum number of digits after the decimal before the values are truncated.
• setMinimumFractionDigits() sets the minimum number of digits after the decimal.  It will zero-fill if necessary.
• setMaximumIntegerDigits() and setMinimumIntegerDigits() does the same for integers.  Their usefullness is somewhat limited.
• NumberFormat has a cousin for formatting dates, DateFormat.  We'll talk about him later.


 Example
 
 

Created by:  Brandan Jones January 4, 2002