What happens when you try to pop an element from an empty Stack?

Java MCQ: What happens when you try to pop an element from an empty Stack?

Answer:

Explanation:

When you try to pop an element from an empty stack, it causes an underflow. Underflow is a condition where an operation is attempted on an empty data structure, and there are no elements to remove. In the context of a stack, this means there is no element at the top to be popped, leading to an error condition.

In many programming languages, attempting to pop from an empty stack typically throws an exception or returns an error. For example, in Java, if you use the Stack class and try to pop an element from an empty stack, a EmptyStackException will be thrown:

import java.util.Stack;

public class Main {
    public static void main(String[] args) {
        Stack<Integer> stack = new Stack<>();
        try {
            int topElement = stack.pop(); // Causes EmptyStackException
        } catch (EmptyStackException e) {
            System.out.println("Stack underflow occurred.");
        }
    }
}

In this example, because the stack is empty, attempting to pop an element results in an EmptyStackException. Properly handling such exceptions is crucial in ensuring that your program can deal with unexpected situations like underflow without crashing.

Understanding underflow helps in designing more robust applications, especially when working with dynamic data structures like stacks, where the size can change during runtime. Ensuring that pop operations are only performed when the stack is not empty is a common practice to avoid such errors.

Reference links:

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