Java Vector size() Method

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Description

The Java Vector size() method is used to return the number of components in this vector.

Declaration

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

public int size()

Parameters

NA

Return Value

The method call returns the number of components in this vector.

Exception

NA

Getting Size of a Vector of Integer Example

The following example shows the usage of Java Vector size() method. We're adding couple of Integers to the Vector object using add() method calls per element. Size of the vector is printed using size() method. And using remove(index) method, we're removing one element and size of the vector is again printed.

package com.tutorialspoint;

import java.util.Vector;

public class VectorDemo {
   public static void main(String[] args) {
      
      // create an empty array list 
      Vector<Integer> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add(20);
      vector.add(30);
      vector.add(20);
      vector.add(30);
      vector.add(15);
      vector.add(22);
      vector.add(11);

      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());
	  
      // remove an element at index 2
      vector.remove(2);

      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());
   }
}

Output

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

Vector Size = 7
Vector Size = 6

Setting Size of a Vector of String Example

The following example shows the usage of Java Vector size() method. We're adding couple of Strings to the Vector object using add() method calls per element. Size of the vector is printed using size() method. And using remove(index) method, we're removing one element and size of the vector is again printed.

package com.tutorialspoint;

import java.util.Vector;

public class VectorDemo {
   public static void main(String[] args) {
      
      // create an empty array list
      Vector<String> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add("Welcome");
      vector.add("To");
      vector.add("Tutorialspoint");

      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());
	  
      // remove an element at index 2
      vector.remove(2);

      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());    
   }
}

Output

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

Vector Size = 3
Vector Size = 2

Setting Size of a Vector of Object Example

The following example shows the usage of Java Vector size() method. We're adding couple of Student objects to the Vector object using add() method calls per element. Size of the vector is printed using size() method. And using remove(index) method, we're removing one element and size of the vector is again printed.

package com.tutorialspoint;

import java.util.Vector;

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

      // create an empty vector
      Vector<Student> vector = new Vector<>();

      // use add() method to add elements in the vector
      vector.add(new Student(1, "Julie"));
      vector.add(new Student(2, "Robert"));
      vector.add(new Student(3, "Adam"));
	  
      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());
	  
      // remove an element at index 2
      vector.remove(2);

      // let us print the size of the vector again
      System.out.println("Vector Size = " + vector.size());      
   }
}

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 −

Vector Size = 3
Vector Size = 2