Node.js Practice

This repository contains a collection of Node.js exercises designed to practice various concepts, including server creation, request handling, form processing, cookie management, and basic JavaScript utility functions.

Exercises

Exercise 1: Node.js Functions

This exercise implements a web server using Express.js that exposes several utility functions through different API endpoints. An HTML frontend (exercise1.html) is provided to interact with these functions.

Functionality:

• Find Summation (/findSummation):
  • Accepts a positive integer n.
  • Calculates the sum of all positive integers from 1 to n.
  • Returns false if the input is not a positive integer.
• Uppercase First and Last Letters (/uppercaseFirstandLast):
  • Accepts a string.
  • Capitalizes the first and last letter of each word in the string.
• Find Average and Median (/findAverageAndMedian):
  • Accepts a comma-separated list of numbers.
  • Calculates the average and median of the provided numbers.
• Find Four-Digit Number (/find4Digits):
  • Accepts a string of numbers separated by spaces.
  • Returns the first four-digit number found in the string, or false if none exists.

Running the Exercise:

1. Navigate to the Exercise1 directory:

   cd Exercise1

2. Install the dependencies:

   npm install

3. Start the server:

   npm start

4. Open your web browser and go to http://localhost:3000 to access the functions via the HTML interface.

Exercise 2: Number of Visits Counter

This exercise implements a simple HTTP server that tracks and displays the number of times a user has visited the webpage. It uses cookies to store the visit count and the timestamp of the last visit.

Functionality:

• On the first visit, it displays a welcome message.
• On subsequent visits, it displays:
  • The current visit count (e.g., "Hello, this is the 2nd time that you are visiting my webpage").
  • The date and time of the previous visit.

Running the Exercise:

1. Navigate to the Exercise2 directory:

   cd Exercise2

2. Install the dependencies:

   npm install

3. Start the server:

   npm start

4. Open your web browser and go to http://localhost:3000. Refresh the page to see the visit count and last visit time update.

Exercise 3: Phone Number Checker

This exercise uses Express.js to create a web application that checks if a submitted phone number adheres to a specific format (123-456-7890).

Functionality:

• Provides an HTML form (exercise3.html) to input a name and a phone number.
• Upon submission (POST /check):
  • Validates if the phone number matches the XXX-XXX-XXXX format.
  • Displays a success message with the user's name and phone number if the format is correct.
  • Displays an error message if the format is incorrect, guiding the user to use the correct format.

Running the Exercise:

1. Navigate to the Exercise3 directory:

   cd Exercise3

2. Install the dependencies:

   npm install

3. Start the server:

   npm start

4. Open your web browser and go to http://localhost:3000 to access the phone number checker form.