Finish the method called getDup() that will take a String[] argument arr and return an int. Find and return the number of duplicate elements. Any element is duplicate if it appears in the array more than once. The getDup() method is already called in the main method with an argument.

This is a return method with String[] parameter

Main topics: methods, Scanner, arrays, loops, String

Example:

	String [] arr = {"1","2","aa"',"1"};
	getDup(arr);

output: 
	2
	("1" is duplicated and there are two "1"s so return is 2)

Example:

	String [] arr = {"1","2","aa"',"1", "aa"};
	getDup(arr);

output: 
	4
	("1" is duplicated and there are two "1"s and two "aa"s so return is 4)

Example:

	String [] arr = {"1","g","aabb',"7","7","2","aa"',"7"};
	getDup(arr);

output: 
	3
	("7" is duplicated three times and there is not other duplicate elements so return is 3)