Java Vector isEmpty()用法及代碼示例

Java中的Java.util.Vector.isEmpty()方法用於檢查和驗證Vector是否為空。如果Vector為空，則返回True，否則返回False。

用法:

Vector.isEmpty()

參數：此方法不帶任何參數。

返回值：如果Vector為空，則此函數返回True，否則返回False。

以下示例程序旨在說明Java.util.Vector.isEmpty()方法：

示例1:

// Java code to illustrate isEmpty() 
import java.util.*; 
  
public class VectorDemo { 
    public static void main(String args[]) 
    { 
        // Creating an empty Vector 
        Vector<String> vec_tor = new Vector<String>(); 
  
        // Use add() method to add elements into the Vector 
        vec_tor.add("Welcome"); 
        vec_tor.add("To"); 
        vec_tor.add("Geeks"); 
        vec_tor.add("4"); 
        vec_tor.add("Geeks"); 
  
        // Displaying the Vector 
        System.out.println("Vector:  " + vec_tor); 
  
        // Verifying if the Vector is empty or not 
        System.out.println("Is the Vector empty? "
                           + vec_tor.isEmpty()); 
  
        // Clearing the Vector 
        vec_tor.clear(); 
  
        // Displaying the Vector 
        System.out.println("Vector after clear(): "
                           + vec_tor); 
  
        // Verifying if the Vector is empty or not 
        System.out.println("Is the Vector empty? "
                           + vec_tor.isEmpty()); 
    } 
}

輸出：

Vector:  [Welcome, To, Geeks, 4, Geeks]
Is the Vector empty? false
Vector after clear(): []
Is the Vector empty? true

示例2:

// Java code to illustrate isEmpty() 
import java.util.*; 
  
public class VectorDemo { 
    public static void main(String args[]) 
    { 
        // Creating an empty Vector 
        Vector<Integer> vec_tor = new Vector<Integer>(); 
  
        // Displaying the Vector 
        System.out.println("Vector:  " + vec_tor); 
  
        // Verifying if the Vector is empty or not 
        System.out.println("Is the Vector empty? "
                           + vec_tor.isEmpty()); 
    } 
}

輸出：

Vector:  []
Is the Vector empty? true

相關用法

注：本文由純淨天空篩選整理自kundankumarjha大神的英文原創作品 Vector isEmpty() Method in Java。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。