Download ITGSS Developer Certification: Full-Stack Developer Certification – Questions with Correct and more Exams Computer Science in PDF only on Docsity!
ITGSS Developer Certification: Full-Stack Developer Certification –
Questions with Correct Answers | 100% Pass
To develop a project from scratch, what technologies and languages would you need or what skills a full stack developer should have? - Programming Languages: Full-stack developers should be competent in more than one programming language Front End technologies: You should be familiar with front-end technologies is also important. Frameworks: This requires proficiency in a variety of development frameworks. Databases and caches: As a full stack developer, you should also know about various DBMS (Database Management Systems) technologies. It is helpful to have a basic understanding of caching mechanisms. Design Ability: Having a good understanding of design is also important if you wish to become a successful Full-Stack web developer. Moreover, the person should be aware of the principles of prototyping and UX/UI design. Server: Good knowledge of Linux helps enormously when administering servers. Explain Pair Programming - In pair programming, two programmers share only one machine and work together. During the development process, one programmer will be the driver who codes and another will act as the observer (navigator) who will make sure the code is written correctly, proofread and spell-check it, while also deciding where to go next. Roles can be swapped at any time: the driver becomes the observer and vice versa. You can also call it "pairing", "paired programming", or "programming in pairs". What do you mean by CORS (Cross-Origin Resource Sharing) - CORS refers to cross-origin resource sharing. It's a browser mechanism that allows web pages in one domain to have controlled access to resources in other domains (cross-domain requests). This allows scripts that
are run on a browser client to interact with and access resources from other origins. In doing so, it extends and provides greater flexibility to the SOP (Same-Origin Policy). Same-origin policies restrict the ability of a website to access resources outside of its source domain. For example, a JavaScript app that wants to make a call to an API (Application Programming Interface) that runs on another domain will be blocked due to the SOP. A CORS policy was implemented to circumvent restrictions caused by same-origin policies. What is Callback Hell? - Callback Hell, or Pyramid of Doom, is a common anti-pattern seen in asynchronous programming code (multiple functions running at the same time). This slang term describes a large number of nested "if" statements or functions. In simple terms, Callback hell is a situation where you have multiple asynchronous functions. Those functions depend on one another, so it could get quite messy with so many callback functions nested in so many layers. The use of callback functions leaves you with code that is difficult to read and maintain, and looks like a pyramid as shown below: This also makes it more difficult to identify the flow of the application, which is the main obstacle to debugging, which is the reason for the famous name of this problem: Callback Hell. Explain Long Polling. - Long polling is defined as a web application development technique used to push information/data from servers to clients as quickly as possible. When a request is made from the client to the server, long-polling maintains the connection between the two. This connection is maintained until the information is ready to be sent from the server to the client. Once a server receives a request from a client, the connection does not close immediately; the connection is only closed once the server has sent the data back to the client or when a timeout threshold has been reached (connection timeout). Can you tell me what are the latest trends in Full Stack Development? Also, how do you keep yourself updated about the new trends in the industry? - Each business needs emerging technology to thrive, whether it is mobile or web application development. This is why they hire front-end developers, back-end developers, or full-stack developers depending on their technology needs. According to industry experts, candidates who are passionate about full- stack development should be aware of these trends:
The response time of the application is improved since requests from one thread do not block requests from other threads. Consequently, if one of the threads encounters an exception, it will not affect the other threads. Multithreading, on the other hand, uses fewer resources than running multiple processes simultaneously. The overhead, time usage, and management associated with creating processes are much higher when compared to creating and managing threads. Explain advantages of Pair Programming. - Two of them will fix the problem if the driver encounters any issues with the code. The two programmers working on the same program are only 15% slower than if they worked independently instead of 50%. As a result of having another programmer look over your work, you are more likely to write better code. One study showed that it results in 15% fewer bugs than code written by a single programmer. It leads to improved collaboration, higher quality, better code, and sustained improved development practices. During the project, each person teaches the other, resulting in more efficient and expedited knowledge exchange. The team develops better communication skills.
Explain the benefits and drawbacks of using "use strict". - In ECMAScript5, a new feature known as strict mode allows you to run a program or function within a strict operating context. Certain actions, therefore, cannot be taken due to this strict context, and more exceptions are thrown. When the "use strict" statement is used, the browser is instructed to use "strict" mode, which is a more restricted and safer JavaScript feature set. You can specify "use strict" at the top of a function to evaluate the JS in strict mode. In strict mode, more errors are thrown and some features are disabled to make your code more robust, clear, and accurate. Explain the advantages of using "use strict". - Errors are thrown when some common coding mistakes are detected. By having strict mode, mistakes that make JavaScript engines tough to optimize can be fixed. Sometimes, strict mode code runs faster than similar, non-strict mode code. Generally, it prevents or throws an error when an "unsafe" action is taken (for example, accessing the global object). It disables poorly thought-out or confusing features. Strict mode simplifies the process of writing "secure" JavaScript. Explain the disadvantages of using "use strict". - Many of the functions that most developers use are absent. It is not possible to access function. Caller or function arguments anymore. If you concatenate scripts written in different strict modes, you may encounter problems.
Keep JavaScript and CSS in external files: Embedding JavaScript and CSS in HTML documents forces them to be downloaded every time the HTML document is loaded. In this case, browser caching is not utilized, and the HTML document becomes larger. This is why you should always place CSS and JavaScript in external files; it is a best practice and simplifies maintenance. Reducing redirects: Too many redirects will delay the loading time of a website. HTTP requests and responses are delayed each time a page redirects. Getting rid of unnecessary redirects on your site will reduce the load time of your site significantly. Load CSS and JavaScript files asynchronously: Your website contains CSS and JavaScript files that can be loaded either synchronously or asynchronously. As part of synchronous loading, each file is loaded sequentially, in the order it appears on your site. As opposed to synchronous loading, asynchronous loading allows multiple files to be loaded simultaneously, boosting the performance of a website. Minify HTML, CSS, and JavaScript: If you optimize the way your files load, your pages will load more quickly. You can do the same when it comes to HTML, CSS, and JavaScript code. By eliminating unnecessary spaces, characters, and comments, you can reduce the size of your files. This will make your web pages load faster. Explain dependency injection. - The Dependency Injection (DI) pattern is a design pattern for implementing the Inversion of Control (IoC). Dependent objects can be created outside of classes and made available to classes in different ways. Three types of classes are involved in Dependency Injection as follows: Client Class: A client class (dependent class) is one that depends on the service class. Service Class: Service (dependency) classes provide services to client classes. Injector Class: This class injects the objects from the service class into the client class.
- What do you mean by observer pattern? - If several objects are tied together in one- to-many relationships, the observer pattern is used. Every time one object is modified, then all of its dependent objects are automatically notified and updated. It falls under the behavioural pattern category. It describes the coupling between the objects and the observer and provides support for broadcast-type communication. The object that observes the state of another object is known as the observer, and the object that is being observed is known as the subject as shown below: State difference between blue/green deployment and rolling deployment. - Today, the software is rapidly created and features are often changed based on customer needs, and then it is deployed into production. Each organization has its unique way of getting new applications into the production environment. Most organizations follow the standard deployment and release strategies such as Blue-Green and Rolling Deployment. Blue-Green Deployment Strategy: A deployment strategy like this creates two separate infrastructure environments i.e., blue and green. A blue environment contains older code (old version), while a green environment (production) contains the latest code (new version). There is only one live production environment at any given time. Example: For instance, the green environment is live and is receiving all user traffic, while the clone (blue) is idle. Once a new version of an application is ready for release, it can be deployed to the blue environment for testing. As soon as the new release passes testing, application traffic is switched from green to blue. Blue then becomes the live production environment, and Green becomes idle, ready for testing the next release. Rolling Deployment Strategy: Using this deployment strategy, old versions of an application are completely replaced with the new versions by completely replacing the infrastructure on which they run. Example: When a new version must be deployed to all nodes, the new version is deployed to the first node while all other nodes handle end-user traffic. As soon as the new version is
What is Promise and explain its states? - Callback functions are functions that can be passed to another function as arguments and executed there to complete a routine or action. Those functions depend on one another, so it could get quite messy with so many callback functions nested in so many layers. This is what is referred to as callback hell. As an alternative to callbacks in JavaScript, promises are used to handle asynchronous operations. In addition to handling multiple asynchronous operations, they provide better error handling than callbacks. Promises can be a better way for a user to read the code effectively and efficiently, especially when that particular code performs multiple asynchronous operations. The Promise object represents the result of an asynchronous operation (or its failure) and the resulting value. The promise is in one of the following states: Pending: In its initial state, neither fulfilled nor rejected. Fulfilled: Indicating that the operation was successful. Rejected: Indicating that the operation failed. State the difference between GET and POST. - GET and POST are two different HTTP request methods. Explain the Restful API and write its usage. - APIs (Application Programming Interfaces) are sets of rules and protocols that define how software programs or devices can communicate with each other. APIs that conform to the design principles of REST, or representational state transfer, are known as REST APIs. REST APIs may also be referred to as RESTful APIs. Using RESTful APIs, developers can create requests and receive responses via an HTTP request. REST API can also be used for mapping data from a cloud platform to a data warehouse or vice versa. What do you mean by MEAN Stack? - MEAN stands for MongoDB, ExpressJS, AngularJS, and Node.js. It is a collection of JavaScript-based technologies for developing web applications. Despite being a stack of different technologies, all of them are based on the JavaScript
language. It is an ideal solution for building dynamic websites and applications as it is a very user-friendly stack. With this free and open-source stack, you can quickly and easily build web- based prototypes. Do you know how to prevent a bot from scraping your publicly accessible API? - As long as the data within the API is accessible to the public, it will technically not be possible to completely prevent data scraping. It is possible, however, to minimize bot activity (automated computer programs on the internet that perform certain tasks) by throttling or rare limiting. Rare limiting will be able to prevent a certain device from making an unlimited number of requests within a defined time. If too many requests are made beyond the defined limit, a 429 Too Many Attempts HTTP error is thrown. It is vital to record more than just the IP address of the device since the IP address is not unique to each device and can stop the whole network from accessing the API. What makes MVC (Model View Controller) different from MVP (Model View Presenter)? - Developers prefer to develop Android applications by utilizing a software architecture pattern. Architecture patterns allow you to express and define a structural schema for software systems. Developers can easily maintain the software and continue to add features to the software in the future. The two most popular android architecture patterns are MVC (Model View Controller) and MVP (Model View Presenter). What do you mean by Temporal Dead Zone in ES6? - Before ES6, variable declarations were only possible using var. With ES6, we got let and const. Both let and const declarations are block-scoped, i.e., they can only be accessed within the " { } " surrounding them. On the other hand, var doesn't have such a restriction. Unlike var, which can be accessed before its declaration, you cannot access the let or const variables until they are initialized with some value. Temporal Dead Zone is the time from the beginning of the execution of a block in which let or const variables are declared until these variables are initialized. Why should arrow functions not be used in ES6? - One of the most popular features of ES6 is the "arrow functions" (also known as "fat arrow functions"). Arrow functions are a new way to write concise functions. Arrow functions offer a compact alternative to traditional function expressions, but they have limitations and cannot be used in every case.
