Vector removeElement() method in Java with Example

The java.util.Vector.removeElement() method is used to remove first occurrence of particular object. If object is not found then it returns false else it returns true. If a particular object is present inside vector and removeElement() method call on that vector element then this method reduces vector size by 1. 

Syntax:

public boolean removeElement(Object obj)

Parameters: This function accepts object as parameter which is to be removed. 

Return Type: On Successful of deletion this function returns True otherwise this function returns False. 

Exceptions: This method does not raise any exception. 

Below programs illustrates the Vector.removeElement() function. 

Program 1:

Java

// Java program to understand
// about vector.removeElement() function

// because vector is present in this package
import java.util.*;

// Driver Code
public class vector_demo {
    // main method begins here
    public static void main(String[] args)
    {
        // creating vector type object
        Vector<Integer> v
            = new Vector<Integer>();

        // inserting elements into the vector
        v.add(1);
        v.add(2);
        v.add(3);
        v.add(4);
        v.add(5);
        v.add(6);

        // printing vector before deleting element
        System.out.println("Before deleting");
        System.out.println("Vector: " + v);
        System.out.println("Size: " + v.size());

        System.out.println("\nAfter deleting");

        // trying to deleting object 3
        boolean flag = v.removeElement(3);
        if (flag) {
            System.out.println("Element '3' has been removed");
        }
        else {
            System.out.println("Element '3' is not present in Vector");
        }

        System.out.println("Vector: " + v);
        System.out.println("Size: " + v.size());
    }
}

Output:

Before deleting
Vector: [1, 2, 3, 4, 5, 6]
Size: 6

After deleting
Element '3' has been removed
Vector: [1, 2, 4, 5, 6]
Size: 5

Example 2:

Java

// Java program to understand
// about vector.removeElement() function

// because vector is present in this package
import java.util.*;

// Driver Code
public class vector_demo {
    // main method begins here
    public static void main(String[] args)
    {
        // creating vector type object
        Vector<Integer> v = new Vector<Integer>();
        // inserting elements into the vector
        v.add(1);
        v.add(2);
        v.add(3);
        v.add(4);
        v.add(5);
        v.add(6);

        // printing vector before deleting element
        System.out.println("Before deleting");
        System.out.println("Vector: " + v);
        System.out.println("Size: " + v.size());

        System.out.println("\nAfter deleting");

        // trying to deleting object 15
        boolean flag = v.removeElement(15);

        // since object 15 is not present flag will be false
        if (flag) {
            System.out.println("Element '15' has been removed");
        }
        else {
            System.out.println("Element '15' is not present in Vector");
        }

        System.out.println("Vector: " + v);
        System.out.println("Size: " + v.size());
    }
}

Output:

Before deleting
Vector: [1, 2, 3, 4, 5, 6]
Size: 6

After deleting
Element '15' is not present in Vector
Vector: [1, 2, 3, 4, 5, 6]
Size: 6

Time complexity: O(n). // n is the size of the vector.
Space complexity: O(1).