Java Vector trimToSize()方法与实例

Java中 Vector 的 trimToSize() 方法将Vector实例的容量修剪为Vector的当前大小。这个方法用来修剪一个Vector实例到它所包含的元素的数量。

语法

trimToSize()

参数： 它不接受任何参数。

返回值： 它不返回任何值。它将这个Vector实例的容量修剪成它所包含的元素的数量。

下面的程序说明了trimTosize()方法。

例1:

// 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());
    }
}

输出：

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

例2:

// 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());
    }
}

输出：

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