This example uses yet another useful static method from the wrapper class Double. It converts the String parameter, str, to a double value and returns the double:

            double parseDouble(String str)
         

At the end of main there is a call to the static method exit in the System class:

            void exit(int exitValue)
         

This call will terminate a program whenever it is called. It can be placed in any method, not just main.

It is useful when using JOptionPane dialogs to avoid a delay in program termination.