Java Stack containsAll()方法及实例

Java Stack的containsAll()方法是用来检查两个堆栈是否包含相同的元素。它以一个堆栈为参数，如果这个堆栈的所有元素都存在于另一个堆栈中，则返回True。

语法

public boolean containsAll(Collection C)

参数： 参数C是一个集合。这个参数指的是需要在这个堆栈中检查其元素出现的堆栈。

返回值： 如果这个堆栈包含其他堆栈的所有元素，该方法返回True，否则返回False。

下面的程序说明了Stack.containsAll()方法。

程序1 :

// Java code to illustrate
// Stack containsAll()
  
import java.util.*;
  
class StackDemo {
    public static void main(String args[])
    {
  
        // Creating an empty stack
        Stack<String>
            stack = new Stack<String>();
  
        // Use add() method to
        // add elements in the stack
        stack.add("Geeks");
        stack.add("for");
        stack.add("Geeks");
        stack.add("10");
        stack.add("20");
  
        // prints the stack
        System.out.println("Stack 1: "
                           + stack);
  
        // Creating another empty stack
        Stack<String>
            stack2 = new Stack<String>();
  
        // Use add() method to
        // add elements in the stack
        stack2.add("Geeks");
        stack2.add("for");
        stack2.add("Geeks");
        stack2.add("10");
        stack2.add("20");
  
        // prints the stack
        System.out.println("Stack 2: "
                           + stack2);
  
        // Check if the stack
        // contains same elements
        System.out.println("\nDoes stack 1 contains stack 2: "
                           + stack.containsAll(stack2));
    }
}

输出：

Stack 1: [Geeks, for, Geeks, 10, 20]
Stack 2: [Geeks, for, Geeks, 10, 20]

Does stack 1 contains stack 2: true

示例2

// Java code to illustrate boolean containsAll()
  
import java.util.*;
  
class StackDemo {
    public static void main(String args[])
    {
  
        // Creating an empty stack
        Stack<String>
            stack = new Stack<String>();
  
        // Use add() method to
        // add elements in the stack
        stack.add("Geeks");
        stack.add("for");
        stack.add("Geeks");
  
        // prints the stack
        System.out.println("Stack 1: "
                           + stack);
  
        // Creating another empty stack
        Stack<String>
            stack2 = new Stack<String>();
  
        // Use add() method to
        // add elements in the stack
        stack2.add("10");
        stack2.add("20");
  
        // prints the stack
        System.out.println("Stack 2: "
                           + stack2);
  
        // Check if the stack
        // contains same elements
        System.out.println("\nDoes stack 1 contains stack 2: "
                           + stack.containsAll(stack2));
    }
}

输出：

Stack 1: [Geeks, for, Geeks]
Stack 2: [10, 20]

Does stack 1 contains stack 2: false