Java Stack isEmpty()用法及代碼示例

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

用法:

Stack.isEmpty()

參數：此方法不帶任何參數。

返回值：如果Stackis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.Stack.isEmpty()方法：

示例1:

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

輸出：

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

示例2:

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

輸出：

Stack:  []
Is the Stack empty? true

相關用法

注：本文由純淨天空篩選整理自Code_r大神的英文原創作品 Stack isEmpty() method in Java with Example。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。