Vector trimToSize() method in Java with Example

The trimToSize() method of Vector in Java trims the capacity of an Vector instance to be the Vector’s current size. This method is used to trim an Vector instance to the number of elements it contains. 

Syntax: 

trimToSize()

Parameter: It does not accepts any parameter. 

Return Value: It does not returns any value. It trims the capacity of this Vector instance to the number of the element it contains. Below program illustrate the trimTosize() method: 

Example 1:

Java

// Java code to demonstrate the working of
// trimTosize() method in Vector

import java.util.Vector;

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

        // creating an Empty Integer Vector
        Vector<Integer> vector
            = new Vector<Integer>(9);

        // using add(), add 5 values
        vector.add(2);
        vector.add(4);
        vector.add(5);
        vector.add(6);
        vector.add(11);

        // Displaying the Vector
        System.out.println("Initial Vector is: " + vector);

        // Displaying the Vector
        System.out.println("Initial size is: " + vector.size());

        // trims the size to the number of elements
        vector.trimToSize();

        // Displaying the Vector
        System.out.println("Size after using trimToSize(): "
                           + vector.size());
    }
}

Output:

Initial Vector is: [2, 4, 5, 6, 11]
Initial size is: 5
Size after using trimToSize(): 5

Example 2:

Java

// Java code to demonstrate the working of
// trimTosize() method in Vector

import java.util.Vector;

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

        // creating vector type object
        Vector<String> vector = new Vector<String>();

        // Inserting elements into the table
        vector.add("Geeks");
        vector.add("4");
        vector.add("Geeks");
        vector.add("Welcomes");
        vector.add("You");

        // Displaying the Vector
        System.out.println("Initial Vector is: " + vector);

        // Displaying the Vector
        System.out.println("Initial size is: " + vector.size());

        // trims the size to the number of elements
        vector.trimToSize();

        // Displaying the Vector
        System.out.println("Size after using trimToSize(): "
                           + vector.size());
    }
}

Output:

Initial Vector is: [Geeks, 4, Geeks, Welcomes, You]
Initial size is: 5
Size after using trimToSize(): 5

Time complexity: O(n). // n is the number of elements in the vector.
Auxiliary space: O(n).