Get an iterator from array in Java

Define a method that takes an array as input and return an iterator to traverse the elements.

 

Signature

public static <T> Iterator<T> getIterator(T[] array)

Find the below working application.

 

ArrayIterator.java

package com.sample.app.iterators;

import java.util.Iterator;
import java.util.NoSuchElementException;

public class ArrayIterator<T> implements Iterator<T>, Iterable<T> {

	private final T[] array;
	private int currentIndex;
	private final int length;

	public ArrayIterator(T[] array) {
		if (array == null) {
			throw new IllegalArgumentException("Array can't be null to get an interator");
		}
		this.array = array;
		currentIndex = 0;
		length = array.length;
	}

	@Override
	public boolean hasNext() {
		return currentIndex < length;
	}

	@Override
	public T next() {
		if (currentIndex >= length) {
			throw new NoSuchElementException();
		}
		return array[currentIndex++];
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException();
	}

	@Override
	public Iterator<T> iterator() {
		return this;
	}
}

ArrayIteratorDemo.java

package com.sample.app.arrays;

import java.util.Iterator;

import com.sample.app.iterators.ArrayIterator;

public class ArrayIteratorDemo {

	public static <T> Iterator<T> getIterator(T[] array) {
		return new ArrayIterator<T>(array);
	}

	public static void main(String[] args) {
		ArrayIterator<Integer> iterator = (ArrayIterator)getIterator(new Integer[] { 2, 3, 5, 7, 11 });

		for(Integer ele: iterator) {
			System.out.println(ele);
		}
	}

}

Output

2
3
5
7
11

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