How to check the technology a website is build with?

Checking the technology a website is built with involves inspecting its underlying components, such as the content management system (CMS), web server, programming languages, and frameworks. Here are several methods to uncover the technology stack of a website:

1. Using Online Tools.

Discovering the technology stack of a website becomes effortless with the assistance of online tools. Platforms like BuiltWith and Wappalyzer offer comprehensive reports by analyzing various components, unveiling the intricate web technologies shaping a website.

BuiltWith:

1. Visit BuiltWith.
2. Enter the URL of the website in question.
3. The tool will generate a detailed report outlining the technologies used.

Wappalyzer:

1. Install the Wappalyzer browser extension for Chrome or Firefox.
2. Open the website you want to inspect.
3. Click on the Wappalyzer icon in your browser to view the detected technologies.

2. Check Page Source.

Dive into the digital anatomy of a website by scrutinizing its page source. By right-clicking and exploring the HTML code, you can unveil meta tags, scripts, and comments that serve as clues, unraveling the technological tapestry behind the web interface.

• Right-click on the website page and select "View Page Source" or "Inspect" (depending on your browser).

• Look for meta tags, comments, or scripts that may indicate the use of specific technologies.

3. Loop for Generator Meta Tag.

Embark on a metadata expedition within a website's HTML source code. The presence of a generator meta tag, such as the one indicating WordPress, serves as a breadcrumb leading to the revelation of the content management system (CMS) in use.

<meta name="generator" content="WordPress">

4. WHOIS Loopup.

Unveil the digital footprint of a website through a WHOIS lookup. By exploring information about domain registration, hosting provider details, and registration history, one can glean insights into the foundational elements supporting the website's structure.

• Perform a WHOIS lookup using websites like WHOIS.net.
• Look for information about the web hosting provider, which might give clues about the technology stack.

5. Online Platform.

Peer into the collaborative world of online platforms like GitHub, GitLab, or Bitbucket. These repositories often unveil the source code and development choices behind a website, presenting a community-driven perspective on its technological foundation.

Some Tips:

• Keep in mind that not all information may be accurately disclosed, and some websites may actively hide their technology stack for security reasons.

• Use multiple methods to cross-verify results.

• Understand that the information gathered might not be exhaustive or up-to-date, especially if the website employs security measures to conceal its stack.

By employing these methods, you can gain valuable insights into the technology stack of a website, enabling a better understanding of its underlying infrastructure and development choices.

Stack Implementation Using Queues.

Stack is a linear data structure that can be implemented using many other data structures like array and linked list. In this article, we will use a Queue data structure to implement the stack operations that follow the LIFO (Last In, First Out) principle. 

Implementation of Stack Using Queue.

If you are a little bit familiar with stack and queue data structure you might know that in stack insertion and deletion of elements happen only from one top end and in queue insertion of an element happens from the rear end and deletion happens from the front. 

There are two common approaches to implementing a stack using queues:

• Using Two Queues.
• Using Single Queue.

Let's explore both the approaches,

Stack Implementation Using Two Queues.

Implementing a stack using two queues involves using one queue (Queue1) for storage and the other (Queue2) for assisting in simulating the Last In, First Out (LIFO) behavior of a stack. 

Push Operation: When pushing an element onto the stack, the new element is enqueued into Queue1, the primary storage queue. To maintain the LIFO order, elements from Queue2, if any, are dequeued and enqueued into Queue1. This step effectively reorganizes the elements to ensure the new addition becomes the topmost element in the simulated stack structure.

Pop Operation: Popping an element from the stack involves dequeuing elements from Queue1 until only one element remains. The objective is to remove the top element, mimicking the behavior of a typical stack operation. By continually dequeuing elements and enqueuing them back into Queue1, except for the last remaining element, the desired element to be removed is identified and dequeued.

Illustration:

Code for Stack Implementation Using Queues.

Below is the code implementation of the above approach:

C++ Java Python C#

// C++ program to implement stack using two Queue
#include <iostream>
#include <queue>
using namespace std;

class Stack {
private:
    queue<int> q1, q2;

public:
    // Push operation
    void push(int value) {
        q1.push(value);
    }

    // Pop operation
    void pop() {
        if (isEmpty()) {
            cout << "Stack is empty. Cannot pop." << endl;
            return;
        }

        // Move elements from q1 to q2, except the last element
        while (q1.size() > 1) {
            q2.push(q1.front());
            q1.pop();
        }

        // Pop the last element from q1
        q1.pop();

        // Swap the names of q1 and q2
        swap(q1, q2);
    }

    // Check if the stack is empty
    bool isEmpty() {
        return q1.empty();
    }

    // Display the top element of the stack
    void peek() {
        if (isEmpty()) {
            cout << "Stack is empty." << endl;
            return;
        }

        // Move elements from q1 to q2, except the last element
        while (q1.size() > 1) {
            q2.push(q1.front());
            q1.pop();
        }

        // Peek at the last element in q1
        cout << "Top element: " << q1.front() << endl;

        // Move the last element back to q1
        q2.push(q1.front());
        q1.pop();

        // Swap the names of q1 and q2
        swap(q1, q2);
    }
};

int main() {
    // Example usage of the stack
    Stack stack;

    // Push elements onto the stack
    stack.push(1);
    stack.push(2);
    stack.push(3);

    // Display the top element
    stack.peek();

    // Pop an element
    stack.pop();

    // Display the top element after pop
    stack.peek();

    return 0;
}

// Java code implementation for stack using Two Queue
import java.util.LinkedList;
import java.util.Queue;

public class Main {
    static class Stack {
        private Queue<Integer> q1 = new LinkedList<>();
        private Queue<Integer> q2 = new LinkedList<>();

        // Push operation
        void push(int value) {
            q1.add(value);
        }

        // Pop operation
        void pop() {
            if (isEmpty()) {
                System.out.println("Stack is empty. Cannot pop.");
                return;
            }

            // Move elements from q1 to q2, except the last element
            while (q1.size() > 1) {
                q2.add(q1.poll());
            }

            // Pop the last element from q1
            q1.poll();

            // Swap the names of q1 and q2
            Queue<Integer> temp = q1;
            q1 = q2;
            q2 = temp;
        }

        // Check if the stack is empty
        boolean isEmpty() {
            return q1.isEmpty();
        }

        // Display the top element of the stack
        void peek() {
            if (isEmpty()) {
                System.out.println("Stack is empty.");
                return;
            }

            // Move elements from q1 to q2, except the last element
            while (q1.size() > 1) {
                q2.add(q1.poll());
            }

            // Peek at the last element in q1
            System.out.println("Top element: " + q1.peek());

            // Move the last element back to q1
            q2.add(q1.poll());

            // Swap the names of q1 and q2
            Queue<Integer> temp = q1;
            q1 = q2;
            q2 = temp;
        }
    }

    public static void main(String[] args) {
        // Example usage of the stack
        Stack stack = new Stack();

        // Push elements onto the stack
        stack.push(1);
        stack.push(2);
        stack.push(3);

        // Display the top element
        stack.peek();

        // Pop an element
        stack.pop();

        // Display the top element after pop
        stack.peek();
    }
}

# Python program to implement stack using Two Queue
from queue import Queue

class Stack:
    def __init__(self):
        self.q1 = Queue()
        self.q2 = Queue()

    # Push operation
    def push(self, value):
        self.q1.put(value)

    # Pop operation
    def pop(self):
        if self.is_empty():
            print("Stack is empty. Cannot pop.")
            return

        # Move elements from q1 to q2, except the last element
        while self.q1.qsize() > 1:
            self.q2.put(self.q1.get())

        # Pop the last element from q1
        self.q1.get()

        # Swap the names of q1 and q2
        self.q1, self.q2 = self.q2, self.q1

    # Check if the stack is empty
    def is_empty(self):
        return self.q1.qsize() == 0

    # Display the top element of the stack
    def peek(self):
        if self.is_empty():
            print("Stack is empty.")
            return

        # Move elements from q1 to q2, except the last element
        while self.q1.qsize() > 1:
            self.q2.put(self.q1.get())

        # Peek at the last element in q1
        print("Top element:", self.q1.queue[0])

        # Move the last element back to q1
        self.q2.put(self.q1.get())

        # Swap the names of q1 and q2
        self.q1, self.q2 = self.q2, self.q1

# Example usage of the stack
stack = Stack()

# Push elements onto the stack
stack.push(1)
stack.push(2)
stack.push(3)

# Display the top element
stack.peek()

# Pop an element
stack.pop()

# Display the top element after pop
stack.peek()

// C-Sharp program to implement stack using Queues
using System;
using System.Collections.Generic;

public class StackUsingQueue {
    class Stack {
        private Queue<int> q1 = new Queue<int>();
        private Queue<int> q2 = new Queue<int>();

        // Push operation
        public void Push(int value) {
            q1.Enqueue(value);
        }

        // Pop operation
        public void Pop() {
            if (IsEmpty()) {
                Console.WriteLine("Stack is empty. Cannot pop.");
                return;
            }

            // Move elements from q1 to q2, except the last element
            while (q1.Count > 1) {
                q2.Enqueue(q1.Dequeue());
            }

            // Pop the last element from q1
            q1.Dequeue();

            // Swap the names of q1 and q2
            Queue<int> temp = q1;
            q1 = q2;
            q2 = temp;
        }

        // Check if the stack is empty
        public bool IsEmpty() {
            return q1.Count == 0;
        }

        // Display the top element of the stack
        public void Peek() {
            if (IsEmpty()) {
                Console.WriteLine("Stack is empty.");
                return;
            }

            // Move elements from q1 to q2, except the last element
            while (q1.Count > 1) {
                q2.Enqueue(q1.Dequeue());
            }

            // Peek at the last element in q1
            Console.WriteLine("Top element: " + q1.Peek());

            // Move the last element back to q1
            q2.Enqueue(q1.Dequeue());

            // Swap the names of q1 and q2
            Queue<int> temp = q1;
            q1 = q2;
            q2 = temp;
        }
    }

    static void Main() {
        // Example usage of the stack
        Stack stack = new Stack();

        // Push elements onto the stack
        stack.Push(1);
        stack.Push(2);
        stack.Push(3);

        // Display the top element
        stack.Peek();

        // Pop an element
        stack.Pop();

        // Display the top element after pop
        stack.Peek();
    }
}

Output:

Top element: 3
Top element: 2

Time and Space Complexity.

In the above code, our pop operation is costly as we have to move all the remaining elements from Queue1 to Queue2. Similarly, we can implement the same approach by making push operation costly instead of pop operation.

Stack Operation	Time Complexity	Space Complexity
Push Operation	O(1)	O(1)
Pop Operation	O(N)	O(1)
IsEmpty	O(1)	O(1)

This approach cleverly utilizes two queues to represent stack behavior by employing element movements between the queues. While it successfully emulates a stack, it incurs some space overhead and may involve extra operations, such as queue swapping which could impact performance.

Stack Implementation using Single Queue.

In the above approach, we have used two queues to implement the stack operation. In this approach, we are going to use a single queue to implement the stack by manipulating the enqueue and dequeue operations to achieve the Last In, First Out (LIFO) behavior of the stack. 

Stack Operations:

Let's understand how we will implement two important stack operations push and pop using a single Queue:

Push Operation: To push an element onto the stack, enqueue the new element into the queue. To move the new element to the top, we have to rearrange elements in the queue by dequeuing elements before the newly added element and enqueuing them back to the queue.

Pop Operation: Popping is quite simple in this approach, we just have to dequeue and return the front element, which represents the topmost element of the stack.

Code for Stack Implementation Using Single Queue.

Below is the code implementation of the above approach:

C++ Java Python C#

// C++ program to implement stack using single Queue
#include<iostream>
#include<queue>
using namespace std;

class StackWithQueue {
private:
    queue<int> myQueue;
public:
    // function to push an element onto the stack
    void push(int value) {
        //get current size of queue
        int queueSize = myQueue.size();

        //enqueue a new element into queue
        myQueue.push(value);

        // rearrange the elements in the queue to 
        // make the new element the front (top)
        for(int i = 0; i < queueSize; i++) {
            myQueue.push(myQueue.front());
            myQueue.pop();
        }
    }
    // function to pop an element from the stack
    void pop() {
        if(myQueue.empty()) {
            cout << "Stack is Empty!"<<endl;
        }
        else {
            myQueue.pop();
        }      
    }
    // function to peek top element
    int peek() {
        if(myQueue.empty()){
            cout<< "Stack is Empty!"<<endl;
            return -1;
        }
        else {
            return myQueue.front();    
        }
    }
    // function to check if stack is empty
    bool isEmpty(){
        return myQueue.empty();
    }
    // function to get the size of stack
    int size() {
        return myQueue.size();
    }
};

//main function
int main() {
    StackWithQueue stack;

    stack.push(1);
    stack.push(2);
    stack.push(5);
    stack.push(8);
    
    cout<< stack.peek() <<endl;
    stack.pop();
    cout<< stack.peek() <<endl;

    return 0;
}

// Java Program to implement stack using Single Queue
import java.util.LinkedList;
import java.util.Queue;

public class StackWithQueue {
    private Queue<Integer> myQueue = new LinkedList<>();

    // Function to push an element onto the stack
    public void push(int value) {
        int queueSize = myQueue.size();
        myQueue.add(value);

        for (int i = 0; i < queueSize; i++) {
            myQueue.add(myQueue.poll());
        }
    }

    // Function to pop an element from the stack
    public void pop() {
        if (myQueue.isEmpty()) {
            System.out.println("Stack is Empty!");
        } else {
            myQueue.poll();
        }
    }

    // Function to peek top element
    public int peek() {
        if (myQueue.isEmpty()) {
            System.out.println("Stack is Empty!");
            return -1;
        } else {
            return myQueue.peek();
        }
    }

    // Function to check if the stack is empty
    public boolean isEmpty() {
        return myQueue.isEmpty();
    }

    // Function to get the size of the stack
    public int size() {
        return myQueue.size();
    }

    // Main function
    public static void main(String[] args) {
        StackWithQueue stack = new StackWithQueue();

        stack.push(1);
        stack.push(2);
        stack.push(5);
        stack.push(8);

        System.out.println(stack.peek());
        stack.pop();
        System.out.println(stack.peek());
    }
}

# Python code Implementation of stack using Single Queue
from queue import Queue

class StackWithQueue:
    def __init__(self):
        self.my_queue = Queue()

    # Function to push an element onto the stack
    def push(self, value):
        queue_size = self.my_queue.qsize()
        self.my_queue.put(value)

        for _ in range(queue_size):
            self.my_queue.put(self.my_queue.get())

    # Function to pop an element from the stack
    def pop(self):
        if self.my_queue.empty():
            print("Stack is Empty!")
        else:
            self.my_queue.get()

    # Function to peek top element
    def peek(self):
        if self.my_queue.empty():
            print("Stack is Empty!")
            return -1
        else:
            return self.my_queue.queue[0]

    # Function to check if the stack is empty
    def is_empty(self):
        return self.my_queue.empty()

    # Function to get the size of the stack
    def size(self):
        return self.my_queue.qsize()

# Main function
if __name__ == "__main__":
    stack = StackWithQueue()

    stack.push(1)
    stack.push(2)
    stack.push(5)
    stack.push(8)

    print(stack.peek())
    stack.pop()
    print(stack.peek())

// C# Program to implement stack using single Queue
using System;
using System.Collections.Generic;

public class StackWithQueue
{
    private Queue<int> myQueue = new Queue<int>();

    // Function to push an element onto the stack
    public void Push(int value)
    {
        int queueSize = myQueue.Count;
        myQueue.Enqueue(value);

        for (int i = 0; i < queueSize; i++)
        {
            myQueue.Enqueue(myQueue.Dequeue());
        }
    }

    // Function to pop an element from the stack
    public void Pop()
    {
        if (myQueue.Count == 0)
        {
            Console.WriteLine("Stack is Empty!");
        }
        else
        {
            myQueue.Dequeue();
        }
    }

    // Function to peek top element
    public int Peek()
    {
        if (myQueue.Count == 0)
        {
            Console.WriteLine("Stack is Empty!");
            return -1;
        }
        else
        {
            return myQueue.Peek();
        }
    }

    // Function to check if the stack is empty
    public bool IsEmpty()
    {
        return myQueue.Count == 0;
    }

    // Function to get the size of the stack
    public int Size()
    {
        return myQueue.Count;
    }

    // Main function
    public static void Main()
    {
        StackWithQueue stack = new StackWithQueue();

        stack.Push(1);
        stack.Push(2);
        stack.Push(5);
        stack.Push(8);

        Console.WriteLine(stack.Peek());
        stack.Pop();
        Console.WriteLine(stack.Peek());
    }
}

Output:

8
5

Time and Space Complexity.

Stack Operation	Time Complexity	Space Complexity
Push Operation	O(N)	O(1)
Pop Operation	O(1)	O(1)
IsEmpty	O(1)	O(1)

Stack Implementation Using Array.

Implementing a stack using an array involves using a fixed-size array to store elements and managing the stack operations by manipulating the array's indices. In this article, we will discuss stack implementation using an array and the advantages and disadvantages of using an array for this implementation.

Stack Implementation using Array.

An array provides a contiguous memory block to store stack elements, allowing direct access to elements via their indices. A top pointer or index is used to keep track of the top element of the stack within the array. 

Implementation of stack operations like push, pop, and peek is easy in array as we have direct access to elements using indices, providing constant-time access O(1). However, arrays have a fixed size, limiting the maximum capacity of the stack. 

Let's understand how to implement each stack operation using an array:

First of all, we have to define an array to store stack elements and initialize an index variable (top) to keep track of the top element.

Implement Push Operation:

• Create a push function that takes a value as input.
• Check if the stack is full (array size is reached), and handle overflow if needed.
• Increment the top pointer and insert the value at the incremented index.

Implement Pop Operation:

• Create a pop function.
• Check if the stack is empty (top is -1), and handle underflow if needed.
• Retrieve the value at the top index, decrement the top pointer, and return the value.

Implement Peek Operation:

• Create a peek function.
• Check if the stack is empty.
• Return the value at the top index without modifying the stack.

Implement isEmpty Operation:

• Create an isEmpty function.
• Check if the top pointer is -1 (indicating an empty stack).
• Return True if the stack is empty; otherwise, return False.

Stack Implementation Code.

Below is the code implementation of the stack using an array in C++, Java, Python, and C# language.

C++ Java Python C#

// C++ program to implement stack using array
#include <iostream>
using namespace std;

class Stack {
private:
    static const int MAX_SIZE = 1000; // Maximum size of the stack
    int arr[MAX_SIZE];
    int top;

public:
    Stack() : top(-1) {}

    // Push operation
    void push(int value) {
        if (top >= MAX_SIZE - 1) {
            cout << "Stack Overflow. Cannot push." << endl;
            return;
        }
        arr[++top] = value;
    }

    // Pop operation
    void pop() {
        if (isEmpty()) {
            cout << "Stack is empty. Cannot pop." << endl;
            return;
        }
        top--;
    }

    // Check if the stack is empty
    bool isEmpty() {
        return top == -1;
    }

    // Display the top element of the stack
    void peek() {
        if (isEmpty()) {
            cout << "Stack is empty." << endl;
            return;
        }
        cout << "Top element: " << arr[top] << endl;
    }
};

int main() {
    // Example usage of the stack
    Stack stack;

    // Push elements onto the stack
    stack.push(1);
    stack.push(2);
    stack.push(3);

    // Display the top element
    stack.peek();

    // Pop an element
    stack.pop();

    // Display the top element after pop
    stack.peek();

    return 0;
}

// Java program to implement stack using Array
public class Main {
  private static final int MAX_SIZE = 1000; // Maximum size of the stack

  static class Stack {
      private int[] arr;
      private int top;

      Stack() {
          arr = new int[MAX_SIZE];
          top = -1;
      }

      // Push operation
      void push(int value) {
          if (top >= MAX_SIZE - 1) {
              System.out.println("Stack Overflow. Cannot push.");
              return;
          }
          arr[++top] = value;
      }

      // Pop operation
      void pop() {
          if (isEmpty()) {
              System.out.println("Stack is empty. Cannot pop.");
              return;
          }
          top--;
      }

      // Check if the stack is empty
      boolean isEmpty() {
          return top == -1;
      }

      // Display the top element of the stack
      void peek() {
          if (isEmpty()) {
              System.out.println("Stack is empty.");
              return;
          }
          System.out.println("Top element: " + arr[top]);
      }
  }

  public static void main(String[] args) {
      // Example usage of the stack
      Stack stack = new Stack();

      // Push elements onto the stack
      stack.push(1);
      stack.push(2);
      stack.push(3);

      // Display the top element
      stack.peek();

      // Pop an element
      stack.pop();

      // Display the top element after pop
      stack.peek();
  }
}

# Python code to implement stack using array 
class Stack:
MAX_SIZE = 1000  # Maximum size of the stack

def __init__(self):
    self.arr = [0] * self.MAX_SIZE
    self.top = -1

# Push operation
def push(self, value):
    if self.top >= self.MAX_SIZE - 1:
        print("Stack Overflow. Cannot push.")
        return
    self.top += 1
    self.arr[self.top] = value

# Pop operation
def pop(self):
    if self.is_empty():
        print("Stack is empty. Cannot pop.")
        return
    self.top -= 1

# Check if the stack is empty
def is_empty(self):
    return self.top == -1

# Display the top element of the stack
def peek(self):
    if self.is_empty():
        print("Stack is empty.")
        return
    print("Top element:", self.arr[self.top])

# Example usage of the stack
stack = Stack()

# Push elements onto the stack
stack.push(1)
stack.push(2)
stack.push(3)

# Display the top element
stack.peek()

# Pop an element
stack.pop()

# Display the top element after pop
stack.peek()

// C-Sharp Code to implement stack using array
using System;

public class StackArray {
    private const int MAX_SIZE = 1000; // Maximum size of the stack

    class Stack {
        private int[] arr;
        private int top;

        public Stack() {
            arr = new int[MAX_SIZE];
            top = -1;
        }

        // Push operation
        public void Push(int value) {
            if (top >= MAX_SIZE - 1) {
                Console.WriteLine("Stack Overflow. Cannot push.");
                return;
            }
            arr[++top] = value;
        }

        // Pop operation
        public void Pop() {
            if (IsEmpty()) {
                Console.WriteLine("Stack is empty. Cannot pop.");
                return;
            }
            top--;
        }

        // Check if the stack is empty
        public bool IsEmpty() {
            return top == -1;
        }

        // Display the top element of the stack
        public void Peek() {
            if (IsEmpty()) {
                Console.WriteLine("Stack is empty.");
                return;
            }
            Console.WriteLine("Top element: " + arr[top]);
        }
    }

    static void Main() {
        // Example usage of the stack
        Stack stack = new Stack();

        // Push elements onto the stack
        stack.Push(1);
        stack.Push(2);
        stack.Push(3);

        // Display the top element
        stack.Peek();

        // Pop an element
        stack.Pop();

        // Display the top element after pop
        stack.Peek();
    }
}

Output:

Top element: 3
Top element: 2

Advantages of Array-based Stack.

• Implementing a stack using an array is straightforward and requires minimum code compared to linked list implementations.
• Array-based stacks offer efficient access to elements using indices, providing constant-time access O(1).
• Array uses contiguous memory, consuming less memory overhead compared to linked lists which require additional pointers for each node.

Disadvantages of Array-based Stack.

• Arrays have a fixed size, limiting the maximum capacity of the stack. This constraint requires predefined sizing or dynamic resizing logic to handle overflow conditions.
• Dynamic resizing to accommodate more elements involves creating a new array with increased capacity and copying existing elements, resulting in time complexity O(n) for resizing operations.
• If the array's size is significantly larger than the current number of stack elements, it can lead to memory wastage.

Related Post:

• Application of Stack Data Structure.
• Stack Implementation using LinkedList.