The containsAll() method of Java Stack is used to check whether two stacks contain the same elements or not. It takes one stack as a parameter and returns True if all of the elements of this stack is present in the other stack.
Syntax:
public boolean containsAll(Collection C)
Parameters: The parameter C is a Collection. This parameter refers to the stack whose elements occurrence is needed to be checked in this stack.
Return Value: The method returns True if this stack contains all the elements of other stack otherwise it returns False.
Below programs illustrate the Stack.containsAll() method:
Program 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));    }} |
Output:
Stack 1: [Geeks, for, Geeks, 10, 20] Stack 2: [Geeks, for, Geeks, 10, 20] Does stack 1 contains stack 2: true
Program 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));    }} |
Output:
Stack 1: [Geeks, for, Geeks] Stack 2: [10, 20] Does stack 1 contains stack 2: false
