Jio Senior Software Engineer Interview Questions and Answers

Java 8 introduced several new features including lambda expressions, streams, and functional interfaces.

• Lambda expressions: Allow for more concise and readable code by enabling functional programming.

• Streams: Provide a way to work with collections of objects in a more functional style.

• Functional interfaces: Interfaces with a single abstract method, used to enable lambda expressions.

• Optional class: Helps to avoid null p...read more

Spring boot annotations are used to simplify the development process by providing metadata to the Spring framework.

• 1. @SpringBootApplication - Main annotation to indicate the main class of a Spring Boot application.

• 2. @RestController - Annotation for RESTful web services.

• 3. @Autowired - Dependency injection annotation.

• 4. @GetMapping, @PostMapping, @PutMapping, @DeleteMapping - Annotations for mapping HTTP requests to c...read more

String Builder is not synchronized and faster, while String Buffer is synchronized and slower.

• String Builder is not thread-safe, while String Buffer is thread-safe.

• String Builder is faster due to lack of synchronization, while String Buffer is slower due to synchronization.

• String Builder is recommended for single-threaded operations, while String Buffer is recommended for multi-threaded operations.

String pool is a storage area in memory where strings are stored to optimize memory usage by reusing common strings.

• String pool helps in reducing memory usage by storing only one copy of each unique string.

• Strings created using double quotes are stored in the string pool.

• Strings created using new keyword are not stored in the string pool.

There are two main types of memory in a computer system: stack memory and heap memory.

• Stack memory is used for static memory allocation and is managed by the compiler. It is typically faster but limited in size.

• Heap memory is used for dynamic memory allocation and is managed by the programmer. It is slower but has a larger size.

• Examples: C programming language uses stack memory for function calls and heap memory for dy

Use a subquery to find the second highest rank in a dataset.

• Use a subquery to select the maximum rank from the dataset.

• Then use another subquery to select the maximum rank that is less than the maximum rank found in the first subquery.

A simple program using modulo operator to determine if a number is odd or even.

• Use the modulo operator (%) to check if the number divided by 2 leaves a remainder

• If the remainder is 0, the number is even. If the remainder is 1, the number is odd

• Example: num % 2 == 0 (even), num % 2 == 1 (odd)

Use SQL query with GROUP BY and HAVING clause to find duplicates in a table.

• Use GROUP BY clause to group rows with same values

• Use HAVING clause to filter out groups with count greater than 1

• Example: SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name HAVING COUNT(*) > 1

Angular is a popular open-source front-end web application framework developed by Google.

• Angular is used for building dynamic web applications.

• It allows for the creation of single-page applications.

• Angular uses TypeScript for building applications.

• It provides features like data binding, dependency injection, and routing.

• Angular has a large community and ecosystem of libraries and tools.

• Examples: AngularJS, Angular 2, A

Routing is the process of selecting a path for network traffic to travel from source to destination.

• Routing involves determining the best path for data packets to travel through a network

• Routers use routing tables to make decisions on where to send data packets

• Routing protocols like OSPF and BGP help routers communicate and update routing information

There are various types of forms, such as physical forms, digital forms, legal forms, etc.

• Physical forms: Paper-based forms that are filled out by hand.

• Digital forms: Electronic forms that are filled out online or through software.

• Legal forms: Forms used for legal purposes, such as contracts or agreements.

Lazy loading in Angular is a technique used to load modules only when they are needed, improving performance by reducing initial load time.

• Lazy loading helps in reducing the initial bundle size of the application by loading modules asynchronously.

• It improves the performance of the application by only loading the modules that are required at a particular time.

• Lazy loading is achieved by using the loadChildren property i...read more

The rxjs operator in Angular is used for reactive programming and handling asynchronous data streams.

• RxJS operators are functions that build on the observables foundation to enable sophisticated manipulation of asynchronous data streams.

• Operators can be used to filter, transform, combine, and more on observables.

• Example: map(), filter(), mergeMap(), switchMap()

Testing frameworks are tools that help automate the process of testing software applications.

• Testing frameworks provide a structure for writing and executing test cases.

• They offer features like test data management, test case organization, and reporting.

• Examples include JUnit for Java, NUnit for .NET, and pytest for Python.

To load an Angular application, you can use the Angular CLI command 'ng serve' to start a development server.

• Use the Angular CLI command 'ng serve' to start a development server

• Navigate to the project directory in the terminal and run 'ng serve'

• Open a web browser and go to 'http://localhost:4200/' to view the application