Floating Point Formatting Applet

Here is an applet that formats a double using DecimalFormat.format(). Enter a floating point number (as characters) into the text box and click on the button.

If you enter characters that can't be converted into a double, an error message will be written. If you want to see lots of zeros, enter something like 1E21. Enter 1E999 and see what happens. Experiment a bit with rounding. Enter 1.999999999 and see what happens.