Parameter 0: stringA Parameter 1: stringB Parameter 2: stringC
The command line data are
always Strings.
But this does not prevent you
from entering numbers.
As with run-time input from
the keyboard you use
Integer.parseInt(String)Double.parseDouble(String)
class InputDemo
{
  public static void main ( String[] args )
  {
    int sum = 0;
    for (int j=0; j  < args.length; j++ )
      sum += Integer.parseInt( _______________ );
    System.out.println( "Sum: " + sum );
  }
}
Say that the user started this program with the command line:
C:\>java InputDemo 23 87 13 67 -42