The demand for Java full-stack developers continues to grow. Candidates must prepare for questions that test their technical and practical skills. A full-stack Java developer is skilled in front-end and back-end technologies and can work across the entire web application.
Interview questions for Java Full-stack developers typically focus on Java, web development technologies, database management, and related topics. Full-stack developers have expertise in various tools, such as languages, frameworks, stacks, and databases.
This blog covers some of the most frequently asked interview questions for Java full-stack developers. Whether you're a beginner or an experienced professional, let's begin.
Check here all the questions along with the answers.
Answer: Java is an object-oriented programming language. It runs on various devices, including mobile devices, gaming consoles, medical devices, and notebook computers. The main benefit of developing software in Java is its portability.
Answer: Java full-stack development involves working on a web application, both frontend (client-side) and backend (server-side). We use technologies like HTML, CSS, JavaScript, and frameworks like Angular/React on the front end. We use Java with frameworks like Spring Boot to build RESTful APIs, manage databases, and much more for back-end development.
Answer: A RESTful API is an application programming interface (API) that follows the principle of representational state transfer (REST). It uses standard web technologies like HTTP and URLs to allow client applications to access and manipulate resources on a server.
The main difference between GET and POST HTTP methods is that.
GET requests are commonly used to retrieve information from a server, while POST requests pass and submit data to be processed by the server. In GET requests, the data is visible in the URL, while in POST requests, the data is not visible.
Answer: Creating and managing a website's front-end and back-end is known as full-stack development. A full-stack developer is skilled in front-end technologies, like HTML, CSS, and JavaScript, and back-end technologies, like database management, API development, and server-side programming.
Answer: Docker is an open-source platform that simplifies application development, deployment, and running using containers. Docker offers various benefits, including faster deployment, a consistent environment, scalability, and resource efficiency.
Answer: To develop a web application, you require a front end, a back end, and a database. Front-end technologies include HTML, CSS, and frameworks such as React and Angular. Backend development can be done using Java, Python, Node.js, and others. Databases can be either relational databases, such as MySQL, or NoSQL databases, like MongoDB.
Answer: A <link> tag is used within the <head> section of the HTML document. Inline styles are applied directly to an HTML element using style attributes. Internal styles are defined within the <style> tag inside the <head> section of the HTML document.
Answer: HTML, HyperText Markup Language, and CSS, Cascading Style Sheets, are all foundational technologies for creating web pages. HTML provides structure, while CSS defines style and layout.
Answer: Any function passed as an argument to another function so that it can be executed in that other function is called a callback function. Callback functions are required because many JavaScript actions are asynchronous.
Answer: Java is a complex language used to build sophisticated apps like Android apps, chatbots, etc. JavaScript is a lightweight, interpreted programming language for client-side web page scripting. Java is mainly used for the backend, while JavaScript is used for both the frontend and backend.
Answer: HTML means hypertext markup language, the fundamental language for creating web pages. HTML is a combination of hypertext and markup languages. Hypertext defines the links between web pages, while markup language defines the text within tags, representing the structure of web pages.
Answer: AJAX (Asynchronous JavaScript and XML) permits web pages to load content asynchronously without reloading the entire page. It uses the XMLHTTP object. It sends HTTP queries and dynamically updates portions of the website using the fetch API or the XMLHttpRequest object.
Answer: JavaScript handles asynchronous code using callbacks, promises, and async/await. Each one offers its advantages.
Answer: Learning full-stack development requires mastering front-end technologies, such as HTML, CSS, and JavaScript, and back-end technologies, such as Java, databases, and APIs.
Answer: The difference between Java and Python is
Answer: JavaScript, Python, and Java are frequently used by full-stack developers to create both front-end and back-end applications. JavaScript is popular for front-end development, while Python and Java are widely used for back-end systems.
Answer: Spring Boot is a framework built upon the Spring framework. It decreases the need for complex configuration and helps in rapid development. It makes creating apps ready for production easier by providing setup defaults, embedded servers, and automatic dependency management.
Spring Boot permits the generation of standalone applications that run directly without an external servlet container. Spring Boot allows you to generate standalone applications that run directly without an external servlet container.
Answer: RESTful web services are web services based on REST principles. They use HTTP methods like GET, POST, PUT, and DELETE to communicate between the client and the server. These web services are generally highly scalable, light, and maintainable.
Answer: In web applications, a session represents a continuous interaction between a user’s browser and a server, permitting the server to maintain state across multiple requests. The server remembers who you are and what you’ve been doing on the website.
Answer: The difference between SQL and NoSQL databases is
Answer: An API (application programming interface) is a set of rules and protocols that permit different software applications to communicate with each other. It defines how responses should be structured, allowing seamless data exchange between systems. APIs developed with REST are known as RESTful APIs. Those produced with GraphQL are simply GraphQL APIs
Answer: A promise is an object that represents a value that may not be available yet but will be at some point in the future (or may never be available). JavaScript promises have exactly three states: pending, fulfilled, and rejected.
Answer: The full form of CORS is Cross-Origin Resource Sharing.
Answer: A servlet in Java is a class that extends the functionality of a server, primarily to host web applications. It runs on a web server and is used to extend its capabilities, handling tasks like form submission and database queries.
Answer: In JavaScript, data types specify the kind of values that a variable can hold. There are 8 basic data types in JavaScript, divided into 2 parts. 1. Primitive data types and non-primitive data types.
Primitive data types are Number, String, Boolean, Null, Undefined, BigInt, and Symbol. Nonprimitive data types are objects.
Answer: JavaScript employs 2 types of comment symbols.
The DOM is a programming interface for web documents. It represents the structure of an HTML or XML document as tree nodes, each representing a part of the document.
Answer: In JavaScript, null is a primitive value representing an empty or unknown value. It indicates that a variable or object property has no value assigned to it and that no value exists.
Answer: The “this keyword” in JavaScript refers to the object it belongs to. The object it refers to will vary depending on how and where it is being called.
Answer: MongoDB is a popular NoSQL document database that stores data in JSON-like documents. It provides scalability and flexibility for applications involving unstructured or varied data.
Answer: JSON's full form is JavaScript Object Notation. JSON is a text format for storing and transporting data. JSON is often used when data is sent from a server to a web page.
Answer: The difference between relational and non-relational databases is as follows
1. Relational Database: Relational databases store data in structured tables, with rows and columns. e.g., MySQL, PostgreSQL. It's good for relationships and handling complex queries.
2. Non-relational database: Non-relational databases are offered in flexible formats such as documents and key-value pairs. They're good for unstructured or hierarchical data.
Answer: Environment variables store configuration values outside the program. This is
necessary for 2 reasons.
Answer: Express.js is a minimal and flexible Node.js framework used to build web applications and APIs. It facilitates the creation of RESTful APIs, single-page, and multi-page web applications.
Answer: Django is a Python framework that makes it easy to create websites using Python. It’s a free and open-source framework that provides a structured approach for building web applications.
Answer: MVC (Model-View-Controller) is an architectural design that separates an application into three main components.
Answer: Optimize JavaScript and CSS, utilize a content delivery network, optimize images, use proper formats, minimize HTTP requests, and remove unnecessary plugins.
Answer:
JDK: The JDK Java Development Kit is a complete development environment for creating Java applications, including tools for writing, compiling, and debugging
JRE: The Java Runtime Environment that executes Java applications, containing the JVM and other libraries.
JVM: The JVM is a virtual machine that provides the execution environment for Java bytecode.
Answer: Variables in Java are containers for storing data values during program execution. They are essential for manipulating and using data within a program. Common data types include int, double, string, boolean, and char.
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CORS stands for cross-origin resource sharing. CORS is a mechanism that permits a web page to access resources from a domain different from the one serving the page using HTTP headers. The Same Origin policy restricts a webpage from requesting a domain different from the one provided to the page.
Java's multithreading feature enables programs to run multiple threads simultaneously, which may enhance CPU efficiency and application responsiveness. A process's lightweight unit is called a thread.
Java Virtual Machine is referred to as JVM. Java virtual machines (JVMs) enable Java programs to run on several platforms. The JVM is essential to Java's "write once, run anywhere, which lets programmers create code that consistently executes across various hardware and operating systems.
Pair programming is a software development technique in which two programmers work together at one workstation and switch roles frequently.
JavaScript manipulates the Document Object Model by offering a programming interface for accessing and changing the structure, content, and style of HTML documents. This is achieved through methods and properties that permit developers to select elements, create new ones, update content, and change attributes or styles.
GraphQL and REST are different approaches to designing and interacting with APIs. REST APIs use standard HTTP methods and various endpoints to access resources, while GraphQL APIs allow clients to query a single endpoint for the needed data.
