Stack.java

//Importing Scanner class for input
import java.util.Scanner;
import java.util.InputMismatchException;

// Stack class
class Stack {
    private int top;
    private int maxSize;
    private int stack[];

    // Constructor for Stack class intialize stack with given maximum size
    public Stack(int maxSize) {
        this.maxSize = maxSize;
        this.stack = new int[maxSize];
        this.top = -1; // stack is empty
    }

    // adding element to stack
    public void push(int element) {
        if (top == maxSize - 1) { // to check stack is full
            System.out.println("-1");
            return;
        }
        stack[++top] = element; // increasing the top and adding element
    }

    // removing element from stack
    public void pop() {
        if (top == -1) { // to check stack is empty
            System.out.println("-1");
            return;
        }
        top--; // decrement top and get element at top of stack
    }

    // to get top of stack
    public int peek() {
        if (top == -1) { // to check stack is empty
            return -1;
        }
        return stack[top]; // get top element of stack
    }

    // method to check empty stack
    public boolean isEmpty() {
        return top == -1;
    }

    // method to check stack is Full
    public boolean isFull() {
        return top == maxSize - 1;
    }

    // to display the stack
    public void display() {
        if (top == -1) { // to check stack is empty
            return;
        }
        for (int index = top; index >= 0; index--) {
            System.out.print(stack[index] + " ");
        }
    }

    public static void main(String[] args) {
        try (Scanner input = new Scanner(System.in)) {
            System.out.println("Enter size of stack you want: ");
            int maxSize = input.nextInt(); // user input for max size
            Stack stack = new Stack(maxSize);
            int choice;
            do {
                System.out.println("1. Push");
                System.out.println("2. Pop");
                System.out.println("3. Peek");
                System.out.println("4. Is empty");
                System.out.println("5. Display");
                System.out.println("6. Exit");
                System.out.println("Enter your choice: ");
                choice = input.nextInt(); // getting user's choice
                switch (choice) {
                    case 1:
                        System.out.println("Enter element to push: ");
                        int element = input.nextInt();
                        if (stack.isFull()) {
                            System.out.println("stack is full");
                            break;
                        }
                        stack.push(element);
                        break;
                    case 2:
                        if (stack.isEmpty()) {
                            System.out.println("Stack is empty");
                            break;
                        }
                        int top = stack.peek();
                        stack.pop();
                        System.out.println("Deleted element is " + top);
                        break;
                    case 3:
                        if (stack.isEmpty()) {
                            System.out.println("Stack is empty");
                            break;
                        }
                        System.out.println("Top element is " + stack.peek());
                        break;
                    case 4:
                        if (stack.isEmpty()) {
                            System.out.println("Stack is empty");
                        } else {
                            System.out.println("Stack is not empty");
                        }
                        break;
                    case 5:
                        if (stack.isEmpty()) {
                            System.out.println("stack is empty");
                            break;
                        }
                        stack.display();
                        System.out.println();
                        break;
                    case 6:
                        System.out.println("Exit done");
                        break;
                    default:
                        System.out.println("Invalid choice");
                }
            } while (choice != 6);
        } catch (InputMismatchException exception) {
            System.out.println(exception);
        } catch (Exception exception) {
            System.out.println(exception);
        }
    }
}