Java Vector removeElement()方法及示例

java.util.Vector .removeElement()方法是用来删除第一次出现的特定对象。如果没有找到对象，则返回false，否则返回true。
如果一个特定的对象存在于向量中，并且在向量元素上调用removeElement()方法，则该方法将向量大小减少1。

语法

public boolean removeElement(Object obj)

参数。这个函数接受要删除的对象作为参数。

返回类型。当删除成功时，该函数返回True，否则该函数返回False。

异常情况。此方法不会引发任何异常。

下面的程序说明了Vector.removeElement()函数。

程序1 :

// 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());
    }
}

输出：

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

例2 :

// 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());
    }
}

输出：

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