What is the use of the args: Array in the main function. Because it seems useless to me
It’s optional
args contains the parameters passed to the executable.
If you start your program from the command line, then those command-line arguments can be the primary means of telling it what to do.⠀(Especially for small utilities and suchlike.⠀For example, if you wrote a word-count program, you could tell it what text file(s) to scan by listing their names on the command line.)
Or they can provide extra information, configuration, or options.⠀(For example, an option could tell your counting program not to show each file’s count separately but only a grand total.)
And even if your program gets started some other way, e.g. from a GUI, it will often have arguments passed to it behind-the-scenes. (For example, you might be able to launch your program by dragging one or more files onto its icon; the names of those files would then be passed to it as command-line arguments.)
Kotlin allows you to omit the parameter if you know you’ll never be using it.⠀But many programs do.