{{parent page="Java"}}
===Core Java Knowledge===
==[[JavaOptions JAVA_OPTS]]==
==[[JavaTimezone Timezone problem under Linux]]==
==[[JavaKeystore Java keystore]]==
==[[JavaSystemOut SystemOut]]==

===Java variable arguments===
One can now write a method that accepts variable number of arguments. For example,
%%(java)
   static double average(double ... numbers)   {
	  double total = 0;
	  for (int i = 0; i < numbers.length; i++)
		   total += numbers [i];
	  return total / numbers.length;
   }
   static String merge(String ... strings)   {
	  StringBuilder sb = new StringBuilder ();
	  for (int i = 0; i < strings.length; i++)
		   sb.append (strings [i]);
	  return sb.toString ();
   }
%%

===Enhanced for loop===
With Java generics, for loops can be simplified. Works on collections and arrays.
%%(java)
ArrayList<String> myFriends = new ArrayList<String>();
myFriends.add("John");
myFriends.add("Peter");
myFriends.add("Mary");
for (String friend : myFriends) {
  System.out.println("Hello " + friend);
}
%%