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Java Vector firstElement() Method

The Java Vector firstElement() method is used to return the first component (the item at index 0) of this vector.

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

public E firstElement()

NA

The method call returns the first component of this vector.

NoSuchElementException − This exception is returned if this vector has no components.

The following example shows the usage of Java Vector firstElement() method to get an element at first position in this vector. We're creating a vector of Integer and added few elements to it using add() method. Then we've printed the element at index 0 using firstElement() method.

package com.tutorialspoint;

import java.util.Vector;

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

      // create an empty Vector vec with an initial capacity of 4      
      Vector<Integer> vec = new Vector<>(4);

      // use add() method to add elements in the vector
      vec.add(4);
      vec.add(3);
      vec.add(2);
      vec.add(1);

      // let us print the first element in the vector
      System.out.println("First element: "+vec.firstElement());
   }    
}

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

First element: 4

The following example shows the usage of Java Vector firstElement() method to get first element in this vector. We're creating a vector of String and added few elements to it using add() method. Then we've printed the first element using firstElement() method.

package com.tutorialspoint;

import java.util.Vector;

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

      // create an empty Vector vec with an initial capacity of 4      
      Vector<String> vec = new Vector<>(4);

      // use add() method to add elements in the vector
      vec.add("D");
      vec.add("C");
      vec.add("B");
      vec.add("A");

      // let us print the first element in the vector
      System.out.println("First element: "+vec.firstElement());
   }    
}

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

First element: D

The following example shows the usage of Java Vector firstElement() method to get first element in this vector. We're creating a vector of Student and added few elements to it using add() method. Then we've printed the first element using firstElement() method.

package com.tutorialspoint;

import java.util.Vector;

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

      // create an empty Vector vec with an initial capacity of 4      
      Vector<Student> vec = new Vector<>(4);

      // use add() method to add elements in the vector
      vec.add(new Student(1, "Julie"));
      vec.add(new Student(2, "Robert"));
      vec.add(new Student(3, "Adam"));
      vec.add(new Student(4, "Jane"));	  

      // let us print the first element in the vector
      System.out.println("First element: "+vec.firstElement());
   }    
}
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);
   }
}

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

First element: [ 1, Julie ]

java_util_vector.htm

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