HCL Infosystems Software Engineer Interview Questions and Answers for Experienced

Abstraction is a concept of hiding implementation details while interface is a contract that defines the behavior of a class.

• Abstraction is achieved through abstract classes and methods

• Interface is a collection of abstract methods

• Abstraction is used for reducing complexity and increasing efficiency

• Interface is used for achieving multiple inheritance and loose coupling

• Abstraction is a way of achieving data abstract...read more

The HashMap class is used to represent key-value pairs in Java.

• HashMap is a part of the Java Collections Framework.

• It allows null values and only one null key.

• It provides constant-time performance for basic operations like get and put.

• Example: HashMap<String, Integer> map = new HashMap<>();

try-catch is used in Java to handle exceptions and prevent program crashes.

• try-catch blocks are used to catch and handle exceptions that may occur during program execution.

• It allows the program to gracefully handle errors and prevent the program from crashing.

• The try block contains the code that may throw an exception, and the catch block handles the exception.

• Multiple catch blocks can be used to handle different ...read more

Abstraction is the process of simplifying complex systems by focusing on essential details and hiding unnecessary complexities.

• Abstraction allows us to create models or representations of real-world objects or systems in software.

• It helps in managing complexity by breaking down a system into smaller, more manageable parts.

• Abstraction provides a level of indirection, allowing changes to be made in one part of the s...read more

Exception handling, stored procedures, indexing, and OOP concepts are important in software engineering.

• Exception handling is the process of handling errors that occur during program execution.

• Stored procedures are pre-written SQL code that can be executed with a single command.

• Indexing is the process of optimizing database performance by creating indexes on frequently queried columns.

• OOP concepts include encapsul...read more