Iterators

Objective

• use iterators in Java

Iterators

• Enumeration
  • first Iterator-style interface in Java
  • only two methods: hasMoreElements() and nextElement()
  • import java.util.Enumeration;
  • see TestEnumeration1.java for sample implementation
  • newer classes often use Iterator instead
• Iterator
  • newer than Enumeration, but very similar
  • three methods: hasNext(), next(), remove()
  • import java.util.Iterator;
  • see TestIterator1.java for sample usage
• ListIterator
  • ListIterators are like Iterators, but with the abilty to step forward AND backward
  • new methods: hasPrevious(), previous()
  • a handfull of other methods have been added: add, set, nextIndex, previousIndex
  • import java.util.ListIterator;
  • see TestIterator2.java for sample usage