El método java.util.Stack.contains() se usa para verificar si un elemento específico está presente en la pila o no. Básicamente, se usa para verificar si una pila contiene algún elemento en particular o no.
Sintaxis:
Stack.contains(Object element)
Parámetros: Este método toma un elemento de parámetro obligatorio que es del tipo de Pila. Este es el elemento que debe probarse si está presente en la pila o no.
Valor de retorno: este método devuelve True si el elemento está presente en la pila; de lo contrario, devuelve False .
Los siguientes programas ilustran el método Java.util.Stack.contains():
Programa 1:
// Java code to illustrate contains()
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);
// Check for "Geeks" in the Stack
System.out.println("Does the Stack contains 'Geeks'? "
+ stack.contains("Geeks"));
// Check for "4" in the Stack
System.out.println("Does the Stack contains '4'? "
+ stack.contains("4"));
// Check if the Queue contains "No"
System.out.println("Does the Stack contains 'No'? "
+ stack.contains("No"));
}
}
Producción:
Stack: [Welcome, To, Geeks, 4, Geeks] Does the Stack contains 'Geeks'? true Does the Stack contains '4'? true Does the Stack contains 'No'? false
Programa 2:
// Java code to illustrate contains()
import java.util.*;
public class StackDemo {
public static void main(String args[])
{
// Creating an empty Stack
Stack<Integer> stack = new Stack<Integer>();
// Use add() method to add elements into the Stack
stack.add(10);
stack.add(15);
stack.add(30);
stack.add(20);
stack.add(5);
// Displaying the Stack
System.out.println("Stack: " + stack);
// Check for "Geeks" in the Stack
System.out.println("Does the Stack contains 'Geeks'? "
+ stack.contains("Geeks"));
// Check for "4" in the Stack
System.out.println("Does the Stack contains '4'? "
+ stack.contains("4"));
// Check if the Stack contains "No"
System.out.println("Does the Stack contains 'No'? "
+ stack.contains("No"));
}
}
Producción:
Stack: [10, 15, 30, 20, 5] Does the Stack contains 'Geeks'? false Does the Stack contains '4'? false Does the Stack contains 'No'? false