Custom Stack Implementation

package com.javatechie.ds;

public class Stack {

    int[] stack = new int[5];
    int top = 0;

    public void push(int element) {
        stack[top] = element;
        top++;
    }

    public int pop() {
        top--;
        int element = stack[top];
        stack[top] = 0;
        return element;
    }

    public int peek() {
        return stack[top - 1];
    }

    public int size() {
        return top;
    }

    public boolean isEmpty() {
        return top == 0 ? true : false;
    }

    public static void main(String[] args) {
        Stack stack = new Stack();
        stack.push(12);
        stack.push(5);
        stack.push(7);
        stack.push(8);
        stack.push(4);

        System.out.println("Element : " + stack.pop());
        System.out.println("peek() : " + stack.peek());
        System.out.println("Size : " + stack.size());
        System.out.println("isEmpty : " + stack.isEmpty());
    }
}