An Introduction to Data Structures - Java Concepts - page 912

LinkedList<String> employeeNames = . . .;
ListIterator<String> iterator =
employeeNames.listIterator();

Note that the iterator class is also a generic type. A ListIterator<String>
iterates through a list of strings; a ListIterator<Product> visits the elements
in a LinkedList<Product> .

Initially, the iterator points before the first element. You can move the iterator
position with the next method:

iterator.next();

The next method throws a NoSuchElementException if you are already past
the end of the list. You should always call the method hasNext before calling
next Ȍit returns true if there is a next element.

if (iterator.hasNext())
iterator.next();

The next method returns the element that the iterator is passing. When you use a
ListIterator<String> , the return type of the next method is String . In
general, the return type of the next method matches the type parameter.

You traverse all elements in a linked list of strings with the following loop:

while (iterator.hasNext())
{
String name = iterator.next();
Do something with name
}

As a shorthand, if your loop simply visits all elements of the linked list, you can use
the Ȓfor eachȓ loop:

668
669

for (String name : employeeNames)
{
Do something with name
}

Then you don't have to worry about iterators at all. Behind the scenes, the for loop
uses an iterator to visit all list elements (see Advanced Topic 15.1 ).