DEV Community: Rahil Sarvaiya

7 steps to crack your next coding Interview

Rahil Sarvaiya — Thu, 24 Jun 2021 17:02:25 +0000

Here are 7 Golden steps to follow to improve your chances of cracking the coding interview 💡

1. Clarify the question with the interviewer. ✔

Make sure you correctly understand the question before you even try and implement it.

2. Confirm the format of the input and the output. ✔

Understanding the input and output format can help visualize the problem better. It can also help in coming up with a solution to the problem.

3. Use test cases and run through a quick example. ✔

Running through an example clarifies with the interviewer that you have understood the problem well. It also gives you an example to test your code once you've completed coding your solution.

4. Brainstorm your approach with the interviewer. ✔

This helps the interviewer know what you're thinking and also correct you if you're on the wrong track. If you're stuck you can think of the various Data Structures that could help solve the problem and move ahead from there.

5. Discuss the Runtime analysis with your interviewer. ✔

If your solution is not the most optimal one, your interviewer will hint at there being a more optimal approach. You must discuss the time and space complexity of your solution.

6. Start coding your solution. ✔

Remember to TALK ALOUD while coding. Your interviewer can't read your mind. Hence, it is important to keep explaining what you're doing to make sure the interview understands your code as well.

7. Debug your code. ✔

Once you have coded your solution, go through it entirely to make sure your code does not have any bugs. Use the example test case in (3) and run that through your code. You must also test your code with certain edge cases, to make sure it won't break.

Next time you prepare for an interview, follow this 7 step process and it will improve your chances of landing that dream job of yours. 🚀

If you liked this article and would like to read similar work, be sure to follow me on Twitter where I’ll post updates about publishing my latest articles.

Please feel free to share your thoughts on this article in the comments section. If you guys have any suggestions regarding this article or on any other interview tips, I would love to know.

What is a REST API?

Rahil Sarvaiya — Sun, 20 Jun 2021 10:28:30 +0000

Have you heard people talk about using REST APIs on the web? Do you know how communication takes place the moment you click something on the internet? Have you wondered how the internet allows you to send and receive data so comfortably? Keep reading to get more information on how communication on the internet works.

What is an API?

Before we dive into what exactly a REST API is, we need to understand the meaning of an API (which stands for Application Programming Interface) and its role in sending and receiving data. According to Wikipedia, API or Application Programming Interface is a computing interface that defines interactions between multiple software intermediaries. Let’s break it down into simpler terms. An API is an interface that helps an application connect to another application. It is the medium through which data can be sent and received between applications on the internet. Every time we are browsing a website on our Laptops, or using an application on our mobile phones, we are essentially using an API.

Let’s try and understand it using a real-life example. Imagine you visit a library and want a particular book. At first glance, you probably won’t be able to find the book, and so you take the help of the librarian asking where this book would be. Now the librarian is left with two options, either he goes to the section of the library, retrieves the book and gives it to you, or directs you to the correct section and makes sure you get the book. He takes your request (of getting Book X) and makes sure you get back a response (get your Book X). This is similar to what an API does, for an online bookstore or book purchasing app (like amazon). When you select a particular book, the API will send the request to the server, the server will check the database if that book is yet available, and then send a response back. The API gets this response and sends it back to you in a legible format that can be interpreted by you. In case of an error, the API will handle this error and send it across in a readable way.

Moreover, APIs also act as an additional level of security. Your phone is never completely exposed on the server, and the server’s data is never fully exposed to your phone. It is through these APIs that the data is sent and received, thus adding an additional level of security by sharing only the necessary bits. Now that you know what an API is, let dive into REST APIs.

REST APIs

REST stands for Representational State Transfer, and was introduced in 2000 by Roy Fielding. REST is an architectural style that consists of 6 constraints that must be satisfied for it to be referred to as RESTful. In simpler terms, it is a set of rules that are followed by developers, to make sure the data is sent and received in a specific format. The API defines how the communication takes place, while REST defines how the API should be formatted. The request sent is the URL and the response is the data that is sent back to you.

The six constraints that should be satisfied for an API to be RESTful are:

1) Uniform Interface

A uniform interface should be used between the client and the server for all the APIs. Once a developer has worked on an API of a class, he should be easily able to work on other APIs of the same class. By applying a uniform interface, the architecture is simplified, and understanding of the APIs is improved. It becomes easier for someone to implement the API, as the standard interface is the same. The four guiding principles of the uniform interface are as follows:

Resource-Based
Manipulation of Resources Through Representations
Self-descriptive Messages
Hypermedia as the Engine of Application State (HATEOAS)

2) Client-Server

The client and server should be two independent separate entities. The client does not deal with data storage, improving client portability and the server does not deal with the user interface, improving server scalability.

3) Stateless

Each request from the client to server must contain all the necessary information as part of the URI, query-string parameters, body, or headers, to process that request. The session state should be present entirely on the client and should not leverage any stored context on the server.

4) Layered System

A layered system improves the architecture and system scalability by enabling load-balancing. Layer systems may also enforce security policies and provide shared caches for better performance.

5) Cacheable

Clients can cache their responses. Thus, the responses must explicitly be labeled as cacheable or non-cacheable to prevent the clients from reusing unfitting data in response to further requests.

6) Code-on-demand (optional)

Client functionality can be extended by executing scripts. Servers can extend their functionality to the client allowing it to execute its logic.

If an API satisfies these above-mentioned constraints, it is
called a RESTful API. REST APIs usually take place over HTTP when used for web APIs. Hence REST APIs make a call from the client to the server and return the response as data over an HTTP protocol.

Hands-On

Now let’s test an API request. For the sake of this example, we will use the Twitter API to get tweets about a specific word we input.

Before testing this API, you will need to make a Twitter Developer Account. After entering your use case for this API, and confirming your email, you will be asked to enter your project name. You can select the project name of your choice, provided it is not already taken, and then you will be given Authorization credentials — an API key, an API secret key, and a Bearer Token. You can use these credentials when you make an API request.

Testing the Twitter API

You can use Postman to test your API. Postman provides tools that make API development easy.

Step 1 - Open a new tab and select the GET request. Enter the API request as shown below.

Step 2 - Click the authorization tab, and enter the Bearer Token as provided for your project while making your Twitter Dev Account.

Step 3 - Make sure you have the following fields in your Headers tab. Your Authorization field with contain your Bearer Token and the Cookie will contain the personalization_id and guest_id which will be unique to you.

Step 4 - Now click the send button and you will be able to view the response below. The response contains the data that satisfied the query parameter as entered by us (vaccine for this example). Each data item contains an id which is the Tweet ID and the text field which is the Tweet Text.

Congrats! You finally made your first API request. Feel free to play around with this API and you can refer to this for more information on using the Twitter API.

Conclusion

I hope you have gained some knowledge of REST APIs and now know how it is used for communication on the internet. If you liked this article and would like to read similar work, be sure to follow me on Twitter where I’ll post updates about publishing my latest articles.

What is JavaScript, Really?

Rahil Sarvaiya — Sat, 19 Jun 2021 05:40:02 +0000

And why is it the most commonly used programming language?

According to the Stack Overflow Survey of 2020, JavaScript has been crowned as the most commonly used programming language for the eighth year in a row. So why is it so popular? What makes developers use it consistently? What’s so special about JavaScript that’s allowed the language to retain the top spot for so long?

JavaScript, often abbreviated as JS, is a dynamic computer programming language. It is the language of the web. It is lightweight and allows you to implement complex features easily on the web. It allows you to create dynamic content on the web, and together with HTML and CSS can be used to make a complete website. JavaScript reduces server interaction, reduces response times, and improves interaction with the user, which makes it an important language for any web application. It is also important to note — programs written in JavaScript are often referred to as “scripts.”

So now that you know what JavaScript is, let’s discuss why it’s being used almost everywhere. The biggest advantage of a multi-paradigm language like JavaScript is that it can be used on the client-side and on the server-side. It can execute on the browser as well on the servers. As a matter of fact, JavaScript can run on any device that has a JavaScript engine. Different web browsers have JavaScript engines that go by different names; for example, the V8 engine on Google Chrome and SpiderMonkey on Firefox.

So how exactly do these engines work? Well, these JavaScript engines that are embedded in a browser read by the JavaScript programs or scripts. They then convert this script into a language that can be understood by the machines called machine language. The machine then executes the code and performs the task.

Now let’s talk about some major frameworks that have adapted JavaScript and use it for client and server-side working. There are two main terms in web development — Frontend Development and Backend Development. The part of the website that interacts directly with the user and includes all the things that the user experiences directly on the screen is called the “Frontend” or “client-side”. The “Backend” or “server-side” is what we call the ‘behind-the-scenes’ work. It refers to the development that happens on the server-side and that makes sure that the client-side is correctly functioning; sending and receiving responses accurately.

Frontend JavaScript

React, Angular, and Vue.js are the three most popular JavaScript frontend frameworks.

React is an open-source JavaScript-based Frontend library that was originally developed by Facebook. React uses a component-based architecture for building user-interfaces.
Angular (or Angular 2+) is a modified version of AngularJS (Angular 1.x) that became obsolete once React came out. It is maintained by Google. Angular is a complete framework compared to React which is only a library. Angular operates on real-DOM and two-way data binding, compared to React which uses virtual DOM and one-way data binding. In addition to this, React being smaller and more compact can sometimes be faster than Angular for smaller applications.
Vue.js, the youngest framework, was developed by an ex-Google employee, Evan You. It leverages concepts used in both React and Angular to build creative interfaces.

Photo on the Github star history of React vs Angular vs Vue from codeinwp

Backend JavaScript

Node.js is an open-source and cross-platform runtime environment that is used for running JavaScript code outside of a web browser. Node.js is not a framework or a language. It is a runtime environment that lets developers write command-line tools and server-side scripts outside of a browser. It is used widely by a large number of companies such as Paypal, Uber, Netflix, and many more.

Node.js — A runtime environment for JavaScript

JavaScript for Mobile Application Development

JavaScript is not limited to web development. With the help of technologies such as React Native (created by Facebook), we can use JavaScript to build mobile applications as well. React Native is an open-source mobile application framework that is used to create native apps using React on Android and iOS using the same code. React Native works in a very similar manner to React, however, React Native does not manipulate the DOM via the virtual DOM. Instead, it runs directly in a background process on the end-device and communicates with the native platform via an asynchronous bridge.

React Native for Mobile App Development from dev.to

In this way, JavaScript can be used in both web and application development. Moreover, with advancing frameworks JavaScript can be used as a Frontend and a Backend language. This not only makes JavaScript a popular language but also encourages the newer developer community to learn it as the same language serves all the purposes.

Why the name JavaScript?

When JavaScript was initially created, it was called “LiveScript”. However, there was another popular language at that time called Java so it was decided that positioning a new language as a “younger brother” of Java would help the evolution of this new language. But as it evolved, JavaScript became a fully independent language with its own specification called ECMAScript, and now it has no relation to Java at all.

Conclusion

I hope you have gained some knowledge of JavaScript and now know why it is one of the most popular programming languages in 2020. If you liked this article and would like to read similar work, be sure to follow me on Twitter where I’ll post updates about publishing my latest articles.

Hacktoberfest 2020 Swagpack

Rahil Sarvaiya — Mon, 04 Jan 2021 12:45:30 +0000

New Year, New Gifts! 👨🏻‍💻😍
Just received my Hacktoberfest swagpack for successfully completing Hacktoberfest 2020. Looking forward to more such contributions in the future.

New M1 chip in the Mac. How do you think it's going to change the development experience?

Rahil Sarvaiya — Tue, 10 Nov 2020 18:51:08 +0000

Never been so excited for an apple upgrade. Is it only me? 😅👨‍💻

Successfully completed Hacktoberfest 2020

Rahil Sarvaiya — Sun, 18 Oct 2020 19:15:15 +0000

What I Learned From Hacktoberfest

Contributing to Hacktoberfest was an amazing experience. This year was the first time I was participating in the event and it was a good learning opportunity. I got introduced to open source technologies and also met some amazing people who helped me in my contributions. Kudos to Digital Ocean, Intel, and Dev for organizing this event and all the participants for completing it with honesty.
Looking forward to continue contributing to Open Source Software in the future.
Do let me know the contributions you made this year and how they impacted you.

Microproductivity — The truth exposed.

Rahil Sarvaiya — Sun, 20 Sep 2020 06:52:55 +0000

Making complex tasks seem more achievable and doable. 🕒

Have you ever got intimidated by the amount of work your colleagues do? Have you ever been surprised at how your friends can study more material than you? Have you been wondering how top CEOs accomplish so much work and yet find time for their hobbies and families? 👀

If you've ever come across any of these questions, I suggest you keep reading to understand the truth behind how smart people work. 💡

Microproductivity is the process of dividing an intricate and complex task, into small and mini-tasks so that they seem more doable and less intimidating.
📚 ➡️ 📗📒📙

Breaking down complex tasks into smaller tasks, makes them feel more achievable. It also reduces our ability to procrastinate. Thinking about the mammoth task ahead of us, will do nothing but scare us or make us feel like the workload is too much to handle. If we keep thinking about how we have so much left to do, we will only get more worried and stressed. Instead, if we break the same enormous task, into smaller tasks, not only will we be able to finish those tasks faster, but at the completion of these smaller tasks, we will feel more satisfied.

How exactly does it work ❔

Breaking down a large project into smaller to-dos helps us identify the steps we need to take next. A simple task seems more approachable and gives us a feeling of mental satisfaction upon completion. Moreover, specificity is really important. The main reason a task appears complex is because we do not know the specifics. If we knew every inch and detail of the project, it would appear easier and more manageable. In the same way, if we divide our tasks into smaller tasks, the specifics of the tasks get known to us. Specific goals force us to pursue them. It makes us think strategically and put in more effort as we have a clear idea of how successful completion will look like.

Need an example?
For example, let's say you are planning on working on your fitness, and want to achieve those 6-pack abs you have always dreamed of. If you keep thinking about achieving those abs, it will feel like an impossible task to achieve. However, if you break it down into small tiny bits, like doing 100 crunches daily, or 500 daily jump ropes, a proper protein-rich diet, daily exercise routines with sufficient rest days, a calorie deficit every day, then our goal will definitely seem more achievable. In fact, we can further break down these tasks into smaller more achievable ones. We can break the 100 crunches into 4 groups of 25 and perform those while watching a movie, or perhaps while watching our favorite football match.
Another example, consider you want to cook a delicious 3-course meal for your family. 🍣🍙🍨 Creating so many dishes, with so much delicacy and minute details, might seem like a cumbersome task. However, if we break this, into 3 separate dishes, separate the ingredients of each dish, slowly and steadily work our way up each dish, progressively approaching one at a time, our complete meal will be ready in no time. In addition to this, at the completion of our first dish, we would feel mentally more pleased that we have succeeded in creating a servable dish. This would boost our confidence, and make us work more strategically to save time on the other dishes.
In this way, by breaking down our big projects into smaller and more achievable tasks, we will be able to accomplish more work. The smaller tasks will feel less intimidating and daunting. If done correctly, it will be the springboard to our success story and our secret to achieving more in less time.

If you need some more help in breaking down your tasks, or if you are confused about how to approach a complex task, I suggest you read this Guide by Christina Willner, which talks about breaking down large projects into bite-sized tasks.
I also suggest visiting the following links, if you want some more detailed information on Microproductivity and the science behind it.

Micro-productivity: Accomplishing Major Goals With Minor Effort

What's Microproductivity? The Small Habit That Will Lead You To Big Wins

Mighty Micro Productivity

Microtasks Might Be the Future of White-Collar Work