JavaScript language brought many new advantages to backend development with its new runtime environment. Here let me outline some of the technical features of the Node runtime environment that makes it different than others. JavaScript is a single-threaded language, which means that it can only execute one instruction at a time. Since the call stack contains the order of instructions to be executed, it means that the JavaScript engine has just one order, one call stack. Node.js is a software program that can execute JavaScript code. Put more properly, Node.js is a JavaScript runtime environment.
Key Functions
Although the getName function is declared inside the object obj, at the time of invocation, getName() is a property of obj2, therefore the “this” keyword will refer to obj2. The debugger for the browser must be activated in order to debug the code. Built-in debuggers may be switched on and off, requiring the user to report faults. The remaining section of the code should stop execution before moving on to the next line while debugging. Hoisting is the default behaviour of javascript where all the variable and function declarations are moved on top. Creating RESTful APIs with Node.js is straightforward, thanks to frameworks like Express.js.
Explain the use of “Passport.js” in Node.js applications.
Whenever you need a third-party package, you install it from NPM using the npm install command. As the event loop runs, it checks if the call stack is empty. If the call stack is not empty, it allows the ongoing process to continue.
What is a first-class function in Javascript?
- As a result, your Node JS interview questions should be able to challenge the candidates’ intellect.
- A class is a generalization of an object, whereas an object is an abstraction of an actual thing.
- To run a Node.js application, simply navigate to the directory containing the application in the terminal, and type “node app.js” (assuming your application is named app.js).
- Node.js provides several tools and frameworks, such as Express.js and Socket.IO, that can be used to build robust front-end applications.
- Most web applications require data persistence, and employers need developers who understand database integration patterns.
- Numerous pages can utilize the same group of JavaScript Codes.
It tells developers what the main components are, how they relate to each other, and what the main purpose of the application is. In addition, poor-quality code can hamper the app’s scaling capacity and the further development of the application. In the worst case scenario, it might become impossible to introduce new features without rewriting the codebase from scratch.
This is maintained to ensure that software quality assurance (QA) analyst an ample number of test cases are executed for the end-to-end development of a project. RESTful API is an architectural style for designing networked applications based on the principles of representational state transfer (REST). Event-driven programming is a technique in which the workflow execution of a program is mainly controlled by the occurrence of events from external programs or other sources. Next, among the Node JS questions you need to know about event-driven programming.
- The following code shows an example of non-blocking(Asynchronous) nature of Nodejs.
- Secondly, separating your app and server can make it easier to scale your application.
- This causes the code to look like a pyramid and makes it unable to read To overcome this situation, we use promises.
- This is because Node.js can handle a large number of connections and can perform non-blocking I/O operations, which makes it ideal for real-time communication.
- This provides them with a large number of wrappers to perform various operations such as ciphering, deciphering, signing, and hashing.
- Hence, using streams will make it easy to process a large set of data in a continuous manner.
NodeJS Interview Questions and Answers
In the case of Node.js, event loops are used for this purpose. Since Node.js supports non-blocking sending, this is a very important feature to have. Node.js works on the single-threaded model to ensure that there is support for asynchronous processing. With this, it makes it scalable and efficient for applications to provide high performance and efficiency under high amounts of load.
A firm favourite amongst first-time developers, RedHat Openshift Online, offers Node.js hosting absolutely free forever – that’s no free-trial period, just free. The Platform-as-a-Service option enables no-fuss cloud hosting, allowing you to focus entirely on improving your applications. You have full control over the server on which your application is run, and you can also run multiple applications on the server, which means lower running costs. Great numbers of unique packages every push cycle create the challenge of conditional dependencies and app scalability. That’s why the company decided to leverage the lightweight and fast Node.js.
Node.js MySQL Tutorial: Create and Manage an Employee Database
Interviewers ask this to evaluate your knowledge of different database technologies and how they integrate with Node.js. They want to see that you can implement efficient, secure database operations. Discuss different performance optimization strategies, including code-level optimizations, database query improvements, caching, load balancing, and hardware scaling. Explain how you identify bottlenecks and measure the impact of optimizations. Interviewers ask this to assess your problem-solving skills and attention to detail. They want to see that you take a methodical approach to performance improvement and understand various optimization techniques.
What are the three methods to avoid callback hell?
Node.js is popular for server-side programming due to its non-blocking, event-driven architecture. This means it can handle multiple client requests simultaneously without waiting for tasks like network requests or database operations to complete. This makes Node.js highly efficient and suitable for real-time applications, such as chat applications, collaborative junior node js developer tools, and gaming servers. This makes Node.js fast, lightweight, scalable, and efficient in handling data-heavy and I/O-heavy workloads characteristic of several types of web applications. The event loop contains a single thread and is responsible for handling easy tasks like executing callbacks and network I/O. When the program is to initialize all the top-level code is executed, the code is not in the callback function.