Java error “Value of local variable is not used”

Question

I am really new to java (started learning 2 days ago). Sorry if this is a stupid question. I am trying to learn how to use rt.exec & similar methods so I tried to make a

Answer 1

You get that error because you don't have the main method that is used to start the java program:

public class main {

public static void main(String[] args) {
   try {
       Runtime rt = Runtime.getRuntime() ;
       Process p = rt.exec("calc.exe") ; // here, eclipse is WARINING(so you can ignore it) you that that the variable p is never used(it's just a warning)
   } catch(Exception exc) {
       /*handle exception*/
       // never do this, always put at least a System.out.println("some error here" + e); so you don't ignore a potential exception
   }
}