Vector set() Method in Java

The Java.util.Vector.set() method is used to replace any particular element in the vector, created using the Vector class, with another element. 

Syntax:

Vector.set(int index, Object element)

Parameters: This function accepts two mandatory parameters as shown in the above syntax and described below.

• index: This is of integer type and refers to the position of the element that is to be replaced from the vector.
• element: It is the new element by which the existing element will be replaced and is of the same object type as the vector.

Return Value: The method returns the previous value from the vector that is replaced with the new value. 

Below programs illustrate the Java.util.Vector.set() method: 

Program 1:

Java

// Java code to illustrate set()
import java.util.*;

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

        // Use add() method to add elements in the vector
        vec_tor.add("Geeks");
        vec_tor.add("for");
        vec_tor.add("Geeks");
        vec_tor.add("10");
        vec_tor.add("20");

        // Displaying the Vector
        System.out.println("Vector: " + vec_tor);

        // Using set() method to replace Geeks with GFG
        System.out.println("The Object that is replaced is: "
                           + vec_tor.set(2, "GFG"));

        // Using set() method to replace 20 with 50
        System.out.println("The Object that is replaced is: "
                           + vec_tor.set(4, "50"));

        // Displaying the modified vector
        System.out.println("The new Vector is:" + vec_tor);
    }
}

Output:

Vector: [Geeks, for, Geeks, 10, 20]
The Object that is replaced is: Geeks
The Object that is replaced is: 20
The new Vector is:[Geeks, for, GFG, 10, 50]

Program 2:

Java

// Java code to illustrate set()
import java.util.*;

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

        // Use add() method to add elements in the vector
        vec_tor.add(12);
        vec_tor.add(23);
        vec_tor.add(22);
        vec_tor.add(10);
        vec_tor.add(20);

        // Displaying the Vector
        System.out.println("Vector: " + vec_tor);

        // Using set() method to replace 12 with 21
        System.out.println("The Object that is replaced is: "
                           + vec_tor.set(0, 21));

        // Using set() method to replace 20 with 50
        System.out.println("The Object that is replaced is: "
                           + vec_tor.set(4, 50));

        // Displaying the modified vector
        System.out.println("The new Vector is:" + vec_tor);
    }
}

Output:

Vector: [12, 23, 22, 10, 20]
The Object that is replaced is: 12
The Object that is replaced is: 20
The new Vector is:[21, 23, 22, 10, 50]

Time complexity: O(n). // n is the size of the vector.
Auxiliary Space: O(n).