User Tools

The Java training online

Back to the table of contents

Solution: 8. Pass parameters on the command line

Try to work with the helping elements before looking at the solution…

Helping elements

  • adapt the main() method of exercise 1 to process 4 parameters
  • note that the 4 parameters will be stored in Strings, in the String[] parameter of main()
  • if you have String[] args, the number of Strings in the array is args.length
  • expected parameters: int numberOfTrees, double xSize, double ySize, String fileName
  • write them in the terminal with a loop
  • interpret the values expected in order: one int value, two double values and a String, store them in 4 variables
  • to turn a String containing digits into an int, use new Integer(String).intValue ()
  • to turn a String containing digits into a double, use new Double(String).doubleValue ()
  • in case of trouble during interpretation (e.g. expected an int and value is not an int…), write an error message in the terminal and throw an exception to the caller
  • send numberOfTrees, xSize and ySize to createTrees ()
  • write a file with the given fileName

A possible solution

An example of solution A case of missing parameters Final output in the terminal

Back to the table of contents

solution_of_8._pass_parameters_on_the_command_line.txt · Last modified: 2021/01/26 15:39 by coligny