iterating through Enumeration of hastable keys throws NoSuchElementException error

Question

I am trying to iterate through a list of keys from a hash table using enumeration however I keep getting a NoSuchElementException at the last key in list?

Hashtable<String, String> vars = new Hashtable<String, String>();  vars.put("POSTCODE","TU1 3ZU"); vars.put("EMAIL","[email protected]"); vars.put("DOB","02 Mar 1983");  Enumeration<String> e = vars.keys();  while(e.hasMoreElements()){  System.out.println(e.nextElement()); String param = (String) e.nextElement(); } 

Console output:

 EMAIL POSTCODE 

 Exception in thread "main" java.util.NoSuchElementException: Hashtable Enumerator     at java.util.Hashtable$Enumerator.nextElement(Unknown Source)     at testscripts.webdrivertest.main(webdrivertest.java:47)  

Answer 1

You call nextElement() twice in your loop. This call moves the enumeration pointer forward. You should modify your code like the following:

while (e.hasMoreElements()) {     String param = e.nextElement();     System.out.println(param); } 

Answer 2

for (String key : Collections.list(e))     System.out.println(key);