Java Vector iterator() Method

Description

The Java Vector iterator() method returns an iterator over the elements in this vector in proper sequence. The iterator is fail-fast means after creation of iterator, any structural modification done to vector object without using iterator.add() or remove() method will lead to ConcurrentModificationException.

Declaration

Following is the declaration for java.util.Vector.iterator() method

public Iterator<E> iterator()

Parameters

NA

Return Value

This method returns an iterator over the elements in this vector in proper sequence.

Exception

NA

Getting Iterator of a Vector of Integer Example

The following example shows the usage of Java Vector iterator() method. We're creating a Vector of Integers. We're adding couple of Integers to the Vector object using add() method calls per element and using iterator() method, we're iterating the vector and print all the elements.

package com.tutorialspoint;

import java.util.Vector;
import java.util.Iterator;

public class VectorDemo {
   public static void main(String[] args) {
      
      // create an empty vector 
      Vector<Integer> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add(0);
      vector.add(1);
      vector.add(2);
      vector.add(3);
      vector.add(4);
      vector.add(5);
      vector.add(6);
	  
      Iterator<Integer> iterator = vector.iterator();
      iterator.forEachRemaining(i -> System.out.println(i));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

0
1
2
3
4
5
6

Getting Iterator of a Vector of String Example

The following example shows the usage of Java Vector iterator() method. We're creating a Vector of Strings. We're adding couple of Strings to the Vector object using add() method calls per element and using iterator() method, we're iterating the vector and print all the elements.

package com.tutorialspoint;

import java.util.Vector;
import java.util.Iterator;

public class VectorDemo {
   public static void main(String[] args) {
      
      // create an empty vector
      Vector<String> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add("A");
      vector.add("B");
      vector.add("C");
	  
      Iterator<String> iterator = vector.iterator();
      iterator.forEachRemaining(i -> System.out.println(i));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

A
B
C

Getting Iterator of a Vector of Object Example

The following example shows the usage of Java Vector iterator() method. We're creating a Vector of Student objects. We're adding couple of Student objects to the Vector object using add() method calls per element and using iterator() method, we're iterating the vector and print all the elements.

package com.tutorialspoint;

import java.util.Vector;
import java.util.Iterator;

public class VectorDemo {
   public static void main(String[] args) {

      // create an empty vector
      Vector<Student> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add(new Student(1, "Julie"));
      vector.add(new Student(2, "Robert"));
      vector.add(new Student(3, "Adam"));

      Iterator<Student> iterator = vector.iterator();
      iterator.forEachRemaining(i -> System.out.println(i));    
   }
}

class Student {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
   
   @Override
   public boolean equals(Object obj) {
      Student s = (Student)obj;
      return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name);
   }
}

Output

Let us compile and run the above program, this will produce the following result −

[ 1, Julie ]
[ 2, Robert ]
[ 3, Adam ]