Clarity

:) yes, sometimes I need help too... But I still don't know what "-c" is:( The requirements of the task and the examples show that the arguments received by main() : - productName is 30 characters and is a string - price is 8 characters and must be a double. etc. But what the hell is "-c"?:) I understand what it is supposed to cause, but: - How many characters is it? - And what type is it?

It's just a made up identifier. You could name it create as well. It does not matter at all. You just pass it to your program when you start it like java myproggie -c value1 value2 value3 Now inside your program you can access your args array and work with that passed data (which of course is of type String). Here the task creator asks you to check the first argument, and if it is equal to -c, you should create a new dataset and save it to file. yeah, yeah... glad to help 😜🤪

OK, I finally get it now, thanx!:)

I often use the command line to test my programs. But until now, I didn't know that this is how to send arguments to start a prg, like this: C:\TEST> java Solution C:\TEST\sourceFile.txt C:\TEST\outFile.txt So thanks for the very useful information!!:) Until now I could only test such argument passing tasks with the following trick:

public static void main(String[] args) throws Exception {
   if (args.length==0) {
        String[] str = new String[1];
        str[0]="C:\TEST\sourceFile.txt";
        main(str);
   }
   if (args.length != 0) {
        // Here was the gist of the code, the whole program
   }
}

:-D

Yippie, an useful information from me 🥳💃🎊🎈 Maybe you can use the next as well. Program arguments are space delimited. However, if you need multiple space-delimited words in one element, you can group these words using quotation marks. eg.: java Solution "Lisa the Great" Lisa the Great inside your program you'll see that args[0] contains "Lisa the Great" whilst args[1] contains "Lisa" Enough chit chat for today, back to the hard work, yeah yeah 🤪😜

Thank you, indeed useful!:)

The main() method accepts arguments just like any other method. These are called command line arguments because they are input when starting the program. IDE's are great and handle a lot of that work for you today, but before their time you literally had to start programs from the command line and add the correct program arguments. Nowadays, however, most programs, even written in java, are started on the GUI with a simple double click and you don't have to go through all those barbaric steps to start a program from the command line interface and enter command line arguments; but that doesn't mean they are completely obsolete. My home computer is a linux machine and there are still programs on it I start from the command line. The command line arguments are similar to this task, where I need a tag (such as "-c") first and then the values. You use different tag/values for different program operations.

Thanks for the explanation.