Java Vector ensureCapacity() Method with Examples

by Online Tutorials Library July 22, 2022

Java Vector ensureCapacity() Method

The ensureCapacity() method of Java Vector class is used to increase the capacity of the vector which is in use, if necessary. It ensures that the vector can hold at least the number of components specified by the minimum capacity argument.

Syntax:

Following is the declaration of ensureCapacity() method:

Parameter:

DataType	Parameter	Description	Required/Optional
int	minCapacity	It is the desired minimum capacity.	Required

Returns:

The ensureCapacity() method has return type void so, it does not return anything.

Exceptions:

Compatibility Version:

Java 1.2 and above

Example 1:

  import java.util.*;  public class VectorEnsureCapacityExample1 {    public static void main(String arg[]) {       //Create an empty vector of capacity 10             Vector<Integer> vec = new Vector<>(10);                    //Ensuring capacity             vec.ensureCapacity(25);                      //Cheking the capacity             System.out.println(“Minimum capacity of this vector: ” +vec.capacity());       }              }  

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Output:

Minimum capacity of this vector: 25

Example 2:

  import java.util.*;  public class VectorEnsureCapacityExample2 {    public static void main(String arg[]) {  //Create an empty vector of capacity 10  Vector<String> vecobject = new Vector<>();  //Add element in the vector  vecobject.add(“50”);   vecobject.add(“green”);  vecobject.add(“red”);   System.out.println(“Element: “+vecobject);  System.out.println(“Capacity of the vector is: ” +vecobject.capacity());  //Increases the capacity of this vector  vecobject.ensureCapacity(20);   System.out.println(“New Capacity of the vector is:” +vecobject.capacity());        }              }  

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Output:

Element: [50, green, red]  Capacity of the vector is: 10  New Capacity of the vector is:20

Example 3:

  import java.util.*;  public class VectorEnsureCapacityExample3 {    public static void main(String arg[]) {  //Create an empty vector of capacity 10  Vector<Integer> vec = new Vector<>(5);        for (int i = 0; i < 10; i++) {           vec.add(0,i);        }        System.out.println(“Element of the vector: “+vec);        System.out.println(“Vector size: “+vec.size());                //Ensure the capacity of the vector and add elements        vec.ensureCapacity(40);        for (int i = 0; i < 10; i++) {           vec.add(0,i);        }            System.out.println(“Vector element after ensuring capacity: “+vec);        System.out.println(“New vector size: “+vec.size());  }              }  

Test it Now

Output:

Element of the vector: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]  Vector size: 10  Vector element after ensuring capacity: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]  New vector size: 20

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Java Vector ensureCapacity() Method with Examples

Java Vector ensureCapacity() Method

Syntax:

Parameter:

Returns:

Exceptions:

Compatibility Version:

Example 1:

Example 2:

Example 3:

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