Java Collection iterator() Method with Examples

by Online Tutorials Library July 22, 2022

Java Collection iterator() Method

The iterator() method of Java Collection Interface returns an iterator over the elements in this collection.

Syntax

Parameters

Return

The iterator () method returns an iterator over the elements in this collection.

Example 1

  import java.util.Collection;  import java.util.Iterator;  import java.util.concurrent.ConcurrentLinkedQueue;  public class JavaCollectionIteratorExample1 {      static int i = 1;      public static void main(String[] args) {          Collection<String> collection = new ConcurrentLinkedQueue<String>();          collection.add(“Ram”);          collection.add(“Sham”);          collection.add(“Mira”);          collection.add(“Rajesh”);          Iterator<String> iterator = collection.iterator();          //Returns an iterator over the elements          while (iterator.hasNext()) {              System.out.println(i++ + “.” + iterator.next());          }      }  }  

Test it Now

Output:

1.Ram  2.Sham  3.Mira  4.Rajesh

Example 2

  import java.util.Collection;  import java.util.Collections;  import java.util.Iterator;  import java.util.concurrent.ConcurrentLinkedQueue;  public class JavaCollectionIteratorExample2 {      public static void main(String[] args) {          Integer[] val = new Integer[2];          Collection<Integer> collection = new ConcurrentLinkedQueue<Integer>();          collection.add(71018);          collection.add(8000);          collection.add(1178);          collection.add(1190);          //Returns an iterator over the elements          Iterator<Integer> iterator = collection.iterator();          while(iterator.hasNext()){              System.out.println(iterator.next());              val[0] = Collections.max(collection);              val[1] = Collections.min(collection);          }          System.out.println(“Max number = “+ val[0]);          System.out.println(“Min number = “+ val[1]);      }  }  

Test it Now

Output:

71018  8000  1178  1190  Max number = 71018  Min number = 1178

Example 3

  import java.util.Collection;  import java.util.Iterator;  import java.util.concurrent.LinkedBlockingDeque;  public class JavaCollectionIteratorExample3 {      public static void main(String[] args) {          Collection<Character> collection = new LinkedBlockingDeque<Character>();          for (char c = ‘a’; c <= ‘z’; c++) {              collection.add(c);          }          System.out.print(“Characters : “);          System.out.print(“[“);          Iterator<Character> iterator = collection.iterator();          //will return the iterator for all characters          while (iterator.hasNext()) {              System.out.print(iterator.next()+” ,”);          }          System.out.println(“]”);      }  }  

Test it Now

Output:

Characters : [a ,b ,c ,d ,e ,f ,g ,h ,i ,j ,k ,l ,m ,n ,o ,p ,q ,r ,s ,t ,u ,v ,w ,x ,y ,z ,]

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Java Collection iterator() Method with Examples

Java Collection iterator() Method

Syntax

Parameters

Return

Example 1

Example 2

Example 3

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