Java Vector insertElementAt() Method

Description

The Java Vector insertElementAt(E obj,int index) method is used to insert the specified object as a component in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously.

Declaration

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

public void insertElementAt(E obj,int index)

Parameters

  • obj − This is the component to insert

  • index − This is the position where to insert the new component.

Return Value

NA

Exception

ArrayIndexOutOfBoundsException − This exception is thrown if the index is invalid.

Inserting Element at a Particular Index in a Vector of Integer Example

The following example shows the usage of Java Vector insertElementAt(Object element int index) method to insert the specified object as a component in this vector at the specified index. We're adding couple of Integer to the Vector object using add() method calls per element, printed the vector and using insertElementAt(Object element, index) method, we're inserting element at index of 1 and printing the updated vector.

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

      // let us insert element at 1st position
      vec.insertElementAt(133, 1);

      System.out.println("Added numbers after insertion :" + vec); 
   }    
}

Output

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

Added numbers are: [4, 3, 2, 1]
Added numbers after insertion :[4, 133, 3, 2, 1]

Inserting Element at a Particular Index in a Vector of String Example

The following example shows the usage of Java Vector insertElementAt(Object element int index) method to insert the specified object as a component in this vector at the specified index. We're adding couple of String to the Vector object using add() method calls per element, printed the vector and using insertElementAt(Object element, index) method, we're inserting element at index of 1 and printing the updated vector.

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

      // let us insert element at 1st position
      vec.insertElementAt("F", 1);

      System.out.println("Added numbers after insertion :" + vec); 
   }    
}

Output

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

Added numbers are: [D, C, B, A]
Added numbers after insertion :[D, F, C, B, A]

Inserting Element at a Particular Index in a Vector of Object Example

The following example shows the usage of Java Vector insertElementAt(Object element int index) method to insert the specified object as a component in this vector at the specified index. We're adding couple of Student objects to the Vector object using add() method calls per element, printed the vector and using insertElementAt(Object element, index) method, we're inserting element at index of 1 and printing the updated vector.

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"));

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

      // let us insert element at 1st position
      vec.insertElementAt(new Student(4, "Jane"), 1);

      System.out.println("Added numbers after insertion :" + 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 + " ]";
   }
}

Output

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

Added numbers are: [[ 1, Julie ], [ 2, Robert ], [ 3, Adam ]]
Added numbers after insertion :[[ 1, Julie ], [ 4, Jane ], [ 2, Robert ], [ 3, Adam ]]
java_util_vector.htm
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