Implement Iterator for Array | N00tc0d3r
public class MyIterable<E> implements Iterable<E> {
E[] elems;
int nElems;
/**
* Constructor.
*/
public MyIterable(E[] data) {
this.elems = data;
nElems = data.length;
}
/**
* Returns an iterator over a set of elements of type E.
*/
public Iterator<E> iterator() {
return new MyIterator<E>();
}
private class MyIterator<E> implements Iterator<E> {
int nextElem = 0;
boolean hasRemoved = true;
/**
* Returns true if the iteration has more elements.
* In other words, returns true if next() would return an element
* rather than throwing an exception.
*/
public boolean hasNext() {
return nextElem < nElems;
}
/**
* Returns the next element in the iteration.
*
* Throws: java.util.NoSuchElementException if the iteration has no more elements
*/
public E next() {
if (!hasNext()) {
throw new NoSuchElementException("No more elements");
}
E e = elems[nextElem];
++nextElem;
hasRemoved = false;
return e;
}
/**
* Removes from the underlying collection the last element returned by this iterator.
* This method can be called only once per call to next(). The behavior of an iterator
* is unspecified if the underlying collection is modified while the iteration is in
* progress in any way other than by calling this method.
*
* Throws: java.lang.IllegalStateException if the next method has not yet been called,
* or the remove method has already been called after the last call to the next method.
*/
public void remove() {
if (hasRemoved) {
throw new IllegalStateException(
"The remove method can only be called once and after the next method.");
}
if (nextElem < nElems - 1) {
System.arraycopy(elems, nextElem+1, elems, nextElem, nElems-nextElem-1);
}
--nElems;
hasRemoved = true;
}
}
}
Read full article from Implement Iterator for Array | N00tc0d3r
public class MyIterable<E> implements Iterable<E> {
E[] elems;
int nElems;
/**
* Constructor.
*/
public MyIterable(E[] data) {
this.elems = data;
nElems = data.length;
}
/**
* Returns an iterator over a set of elements of type E.
*/
public Iterator<E> iterator() {
return new MyIterator<E>();
}
private class MyIterator<E> implements Iterator<E> {
int nextElem = 0;
boolean hasRemoved = true;
/**
* Returns true if the iteration has more elements.
* In other words, returns true if next() would return an element
* rather than throwing an exception.
*/
public boolean hasNext() {
return nextElem < nElems;
}
/**
* Returns the next element in the iteration.
*
* Throws: java.util.NoSuchElementException if the iteration has no more elements
*/
public E next() {
if (!hasNext()) {
throw new NoSuchElementException("No more elements");
}
E e = elems[nextElem];
++nextElem;
hasRemoved = false;
return e;
}
/**
* Removes from the underlying collection the last element returned by this iterator.
* This method can be called only once per call to next(). The behavior of an iterator
* is unspecified if the underlying collection is modified while the iteration is in
* progress in any way other than by calling this method.
*
* Throws: java.lang.IllegalStateException if the next method has not yet been called,
* or the remove method has already been called after the last call to the next method.
*/
public void remove() {
if (hasRemoved) {
throw new IllegalStateException(
"The remove method can only be called once and after the next method.");
}
if (nextElem < nElems - 1) {
System.arraycopy(elems, nextElem+1, elems, nextElem, nElems-nextElem-1);
}
--nElems;
hasRemoved = true;
}
}
}
Read full article from Implement Iterator for Array | N00tc0d3r
