What does java stack mean?

Java Stack class

stack (stack) is a subclass of Vector, which implements a standard last-in-first-out stack.

public class Stack<E>extends Vector<E>

The stack only defines a default constructor, which is used to create an empty stack. In addition to all the methods defined by Vector, the stack also defines some of its own methods.

The Stack class represents a last-in-first-out (LIFO) stack of objects.

It extends class Vector with five operations, allowing vectors to be treated as stacks. It provides the usual push and pop operations, as well as the peek method to take the stack vertex, the empty method to test whether the stack is empty, and the search method to find an item in the stack and determine the distance to the top of the stack.

When a stack is first created, it contains no items.

Direct Stack() creates an empty stack

Example:

import java.util.*;
 
public class StackDemo {
 
    static void showpush(Stack<Integer> st, int a) {
        st.push(new Integer(a));
        System.out.println("push(" + a + ")");
        System.out.println("stack: " + st);
    }
 
    static void showpop(Stack<Integer> st) {
        System.out.print("pop -> ");
        Integer a = (Integer) st.pop();
        System.out.println(a);
        System.out.println("stack: " + st);
    }
 
    public static void main(String args[]) {
        Stack<Integer> st = new Stack<Integer>();
        System.out.println("stack: " + st);
        showpush(st, 42);
        showpush(st, 66);
        showpush(st, 99);
        showpop(st);
        showpop(st);
        showpop(st);
        try {
            showpop(st);
        } catch (EmptyStackException e) {
            System.out.println("empty stack");
        }
    }
}

Result:

stack: [ ]
push(42)
stack: [42]
push(66)
stack: [42, 66]
push(99)
stack: [42, 66, 99]
pop -> 99
stack: [42, 66]
pop -> 66
stack: [42]
pop -> 42
stack: [ ]
pop -> empty stack

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