Which operation is used to remove an element from a Stack?

Java MCQ: Which operation is used to remove an element from a Stack?

Answer:

Explanation:

The operation used to remove an element from a stack is known as “pop.” The pop operation removes the element at the top of the stack, which is the most recently added element, following the Last-In-First-Out (LIFO) principle. After the pop operation, the next element below the top becomes the new top of the stack.

The pop operation is crucial for managing data in a stack, particularly in applications where the most recent data must be accessed or removed first. For example, in undo functionality in software applications, the last action performed (which is the top element of the stack) is the first one to be undone when a pop operation is executed.

Here’s an example of a pop operation in Java using the Stack class:

import java.util.Stack;

public class Main {
    public static void main(String[] args) {
        Stack<Integer> stack = new Stack<>();
        stack.push(10);
        stack.push(20);
        stack.push(30);
        int topElement = stack.pop(); // Removes 30
        System.out.println(topElement); // Outputs: 30
        System.out.println(stack); // Outputs: [10, 20]
    }
}

In this example, the number 30 is popped from the stack, making 20 the new top element. The pop operation is performed in constant time, O(1), which makes it efficient for use in scenarios where elements are frequently added and removed from the stack.

Reference links:

https://www.javaguides.net/p/java-stack-tutorial.html