Java Stack empty()用法及代码示例

Java中的java.util.Stack.empty()方法用于检查堆栈是否为空。该方法为布尔型，如果堆栈为空，则返回true，否则返回false。

用法:

STACK.empty()

参数：该方法不带任何参数。

返回值：如果堆栈为空，则该方法返回boolean true，否则返回false。

以下程序说明了java.util.Stack.empty()方法的用法：
示例1:

// Java code to demonstrate empty() method 
import java.util.*; 
  
public class Stack_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty Stack 
        Stack<String> STACK = new Stack<String>(); 
  
        // Stacking strings 
        STACK.push("Geeks"); 
        STACK.push("4"); 
        STACK.push("Geeks"); 
        STACK.push("Welcomes"); 
        STACK.push("You"); 
  
        // Displaying the Stack 
        System.out.println("The stack is: " + STACK); 
  
        // Checking for the emptiness of stack 
        System.out.println("Is the stack empty? " +  
                                      STACK.empty()); 
  
        // Popping out all the elements 
        STACK.pop(); 
        STACK.pop(); 
        STACK.pop(); 
        STACK.pop(); 
        STACK.pop(); 
  
        // Checking for the emptiness of stack 
        System.out.println("Is the stack empty? " +  
                                     STACK.empty()); 
    } 
}

输出：

The stack is: [Geeks, 4, Geeks, Welcomes, You]
Is the stack empty? false
Is the stack empty? true

示例2:

// Java code to demonstrate empty() method 
import java.util.*; 
  
public class Stack_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty Stack 
        Stack<Integer> STACK = new Stack<Integer>(); 
  
        // Stacking int values 
        STACK.push(8); 
        STACK.push(5); 
        STACK.push(9); 
        STACK.push(2); 
        STACK.push(4); 
  
        // Displaying the Stack 
        System.out.println("The stack is: " + STACK); 
  
        // Checking for the emptiness of stack 
        System.out.println("Is the stack empty? " +  
                                      STACK.empty()); 
    } 
}

输出：

The stack is: [8, 5, 9, 2, 4]
Is the stack empty? false

相关用法

注：本文由纯净天空筛选整理自Chinmoy Lenka大神的英文原创作品 Stack empty() Method in Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。