up previous next contents
Next: Maps Up: Collections framework Previous: Collections framework   Contents

Lists

  • In addition to the standard collection methods, the List interface allows for random access of elements through its get and set methods.
  • List indices are zero based, so list.get(list.size())) is not a valid element.
       List stuff = new ArrayList();
    
       stuff.add("Apple");
       stuff.add("Orange");
    
       // what's the last item? Indexes are zero based!
       System.out.println(stuff.get(stuff.size() - 1));
    
       // change the first item to a pear.  
       stuff.set(0, "Pear");
    
       // now iterate
       Iterator it = stuff.iterator();
    
       while(it.hasNext())
       {
          String item = (String)it.next();
          System.out.println(item);
       }
    

  • ListIterator allows element addition, removal, and replacement during iteration.
  • The java.util package provides two new List implementations: ArrayList and LinkedList.
  • Vector is a legacy class retrofitted to the new Collection framework, and is thread safe.


up previous next contents
Next: Maps Up: Collections framework Previous: Collections framework   Contents