Question

Parameter Mystery. Consider the following program. List below the exact output produced by the above program (we do not claim that every line of output makes sense ;-).

public class Mystery

{ public static void main(String[] args)

{ String john = "skip";

String mary = "george";

String george = "mary";

String fun = "drive"; statement(george, mary, john);

statement(fun, "george", "work");

statement(mary, john, fun);

statement(george, "john", "dance"); }

public static void statement(String mary, String john, String fun)

{ System.out.println(john + " likes to " + fun + " with " + mary); } }

I know the output is

george likes to skip with mary
george likes to work with drive
skip likes to drive with george
john likes to dance with mary

But I don't know why- can I get an explanation as to why???

Answer 1

Code:

/*
   NOTE: Variables declared inside a method and
   it's parameters(e.g statement(String example)) are local
   i.e they are present to use only in that method, and their is
   no problem if any other method have variables with same name,
   because they are different.
*/
public class Mystery {
   /*
       This method will print the value passed to it in parameter john
       then add "likes to" then the value passed to it in fun, then add
       "with" and finally the value passed to it in mary
   */
   public static void statement(String mary, String john, String fun) {
       System.out.println(john + " likes to " + fun + " with " + mary);
   }

   public static void main(String[] args) {
       String john = "skip";
       String mary = "george";
       String george = "mary";
       String fun = "drive";

       // I'll describe each call to the method statement()

       /*
           Inside the statement
           mary = value of george i.e "mary"
           john = value of mary i.e "george"
           fun = value of john i.e "skip"
           System.out.println(john + " likes to " + fun + " with " + mary);
           will print
           System.out.println("george" + " likes to " + "skip" + " with " + "mary");
       */
       statement(george, mary, john);

       /*
           Inside the statement
           mary = value of fun i.e "drive"
           john = "george"
           fun = "work"
           System.out.println(john + " likes to " + fun + " with " + mary);
           will print
           System.out.println("george" + " likes to " + "work" + " with " + "drive");
       */
       statement(fun, "george", "work");

       /*
           Inside the statement
           mary = value of mary i.e "george"
           john = value of john i.e "skip"
           fun = value of fun i.e "drive"
           System.out.println(john + " likes to " + fun + " with " + mary);
           will print
           System.out.println("skip" + " likes to " + "drive" + " with " + "george");
       */
       statement(mary, john, fun);

       /*
           Inside the statement
           mary = value of george i.e "mary"
           john = "john"
           fun = "dance"
           System.out.println(john + " likes to " + fun + " with " + mary);
           will print
           System.out.println("john" + " likes to " + "dance" + " with " + "mary");
       */
       statement(george, "john", "dance");
   }
  
}

OUTPUT: