Java Vector setElementAt() Method

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Description

The Java Vector setElementAt(E obj,int index) method is used to set the component at the specified index of this vector.The previous component at that position is discarded.

Declaration

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

public void setElementAt(E obj,int index)

Parameters

• obj − This is the component is to be set.

• index − This is the specified index where the component will be set.

Return Value

NA

Exception

ArrayIndexOutOfBoundsException − This exception is thrown if the accessed index is out of range.

Setting Element at a Particular Index of a Vector of Integer Example

The following example shows the usage of Java Vector setElementAt(object, index) method. We're adding couple of Integers to the Vector object using add() method calls per element and using setElementAt(object, index) method, we're insert one of the element by index in between and printing it.

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);

      // set 16 at 2nd index position
      vec.setElementAt(22,2);

      // let us print all the elements available in vector
      System.out.println("Added numbers are : " + vec);            
   }
} 

Output

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

Added numbers are : [4, 3, 22, 1]

Setting Element at a Particular Index of a Vector of String Example

The following example shows the usage of Java Vector setElementAt(object, index) method. We're adding couple of Strings to the Vector object using add() method calls per element and using setElementAt(object, index) method, we're insert one of the element by index in between and printing it.

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");

      // set F at 2nd index position
      vec.setElementAt("F",2);

      // let us print all the elements available in vector
      System.out.println("Added elements are : " + vec);            
   }
} 

Output

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

Added elements are : [D, C, F, A]

Setting Element at a Particular Index of a Vector of Object Example

The following example shows the usage of Java Vector setElementAt(object, index) method. We're adding couple of Students to the Vector object using add() method calls per element and using setElementAt(object, index) method, we're insert one of the element by index in between and printing it.

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"));

      // set 16 at 2nd index position
      vec.setElementAt(new Student(4, "Jene"),2);

      // let us print all the elements available in vector
      System.out.println("Added elements are : " + vec);            
   }
}
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.

Added elements are : [[ 1, Julie ], [ 2, Robert ], [ 4, Jene ]]