Module java.base
Package java.util

Interface Enumeration<E>

  • All Known Subinterfaces:
    NamingEnumeration<T>
    All Known Implementing Classes:
    StringTokenizer
    public interface Enumeration<E>
    An object that implements the Enumeration interface generates a series of elements, one at a time. Successive calls to the nextElement method return successive elements of the series.

    For example, to print all elements of a Vector<E> v: 

       for (Enumeration<E> e = v.elements(); e.hasMoreElements();)
       System.out.println(e.nextElement());

    Methods are provided to enumerate through the elements of a vector, the keys of a hashtable, and the values in a hashtable. Enumerations are also used to specify the input streams to a SequenceInputStream.

    Since:
    1.0
    See Also:
    Iterator, SequenceInputStream, nextElement(), Hashtable, Hashtable.elements(), Hashtable.keys(), Vector, Vector.elements()

    • Method Detail

      • hasMoreElements

        boolean hasMoreElements()
        Tests if this enumeration contains more elements.
        Returns:
        true if and only if this enumeration object contains at least one more element to provide; false otherwise.

      • nextElement

        E nextElement()
        Returns the next element of this enumeration if this enumeration object has at least one more element to provide.
        Returns:
        the next element of this enumeration.
        Throws:
        NoSuchElementException - if no more elements exist.

      • asIterator

        default Iterator<E> asIterator()
        Returns an Iterator that traverses the remaining elements covered by this enumeration. Traversal is undefined if any methods are called on this enumeration after the call to asIterator.
        Returns:
        an Iterator representing the remaining elements of this Enumeration
        Since:
        9