Enumeration

public interface Enumeration

java.util.Enumeration<E>

Known indirect subclasses

StringTokenizer The string tokenizer class allows an application to break a string into tokens.

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.

See also:

Summary

Public methods
`default Iterator<E>`	`asIterator()` Returns an `Iterator` that traverses the remaining elements covered by this enumeration.
`abstract boolean`	`hasMoreElements()` Tests if this enumeration contains more elements.
`abstract E`	`nextElement()` Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Public methods

asIterator

Added in API level 33

public 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.

API Note:

This method is intended to help adapt code that produces Enumeration instances to code that consumes Iterator instances. For example, the JarFile.entries() method returns an Enumeration<JarEntry>. This can be turned into an Iterator, and then the forEachRemaining() method can be used:
```
JarFile jarFile = ... ;
     jarFile.entries().asIterator().forEachRemaining(entry -> { ... });
 
```
(Note that there is also a JarFile.stream() method that returns a Stream of entries, which may be more convenient in some cases.)

Implementation Requirements:

The default implementation returns an Iterator whose hasNext method calls this Enumeration's hasMoreElements method, whose next method calls this Enumeration's nextElement method, and whose remove method throws UnsupportedOperationException.

Returns
`Iterator<E>`	an Iterator representing the remaining elements of this Enumeration

hasMoreElements

Added in API level 1

public abstract boolean hasMoreElements ()

Tests if this enumeration contains more elements.

Returns
`boolean`	`true` if and only if this enumeration object contains at least one more element to provide; `false` otherwise.

nextElement

Added in API level 1

public abstract E nextElement ()

Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Returns
`E`	the next element of this enumeration.

Throws
`NoSuchElementException`	if no more elements exist.