Celes'tile Java Developer Interview Questions and Answers

Java is a high-level programming language known for its platform independence and object-oriented approach.

• Java is widely used for developing desktop, web, and mobile applications.

• It is known for its write once, run anywhere (WORA) capability.

• Java uses a virtual machine (JVM) to execute code, providing portability across different operating systems.

• It supports multithreading, exception handling, and dynamic memory allo...read more

Inheritance is a mechanism in object-oriented programming where a new class is created from an existing class.

• Allows for code reuse and promotes code organization

• The new class (subclass) inherits properties and methods from the existing class (superclass)

• Subclass can add new properties and methods or override existing ones

• Example: A Car class can inherit properties and methods from a Vehicle class

Factorial can be calculated using a loop by multiplying numbers from 1 to n.

• Initialize a variable to 1

• Use a loop to multiply the variable with numbers from 1 to n

• Return the variable

Answering questions related to software development and Salesforce administration.

• Process Builder is a visual tool in Salesforce used to automate business processes.

• Types of relationships in Salesforce include lookup, master-detail, and many-to-many relationships.

• User represents an individual who can log in and access Salesforce, Profile defines the permissions and settings for a user, and Role determines the hierarchy...read more

I have configured various software systems and tools for development purposes.

• Configured IDEs such as Eclipse and Visual Studio for development

• Set up version control systems like Git and SVN

• Installed and configured build tools like Maven and Gradle

• Configured application servers like Tomcat and JBoss

• Set up databases like MySQL and Oracle for development and testing

The latest embedded systems are focused on IoT, AI, and machine learning.

• Embedded systems are becoming more connected to the internet of things (IoT)

• AI and machine learning are being integrated into embedded systems for improved performance

• Low-power consumption and high-performance processors are being developed for embedded systems

• Examples include Amazon Echo, Nest Thermostat, and Fitbit

Count the number of pairs in an array whose sum is equal to a given number k.

• Iterate through the array and for each element, check if k minus the element exists in the array.

• Use a hash table to store the frequency of each element in the array.

• If the array contains duplicates, handle them separately to avoid overcounting.

• Time complexity can be improved to O(n) using a two-pointer approach.

Abstraction is the process of hiding complex implementation details and exposing only the necessary information.

• Abstraction helps in reducing complexity and increasing efficiency.

• It allows us to focus on the essential features of an object or system.

• Abstraction can be achieved through abstract classes, interfaces, and encapsulation.

• For example, a car can be abstracted as a vehicle with certain properties and methods.

• Ab...read more

Hiding implementation means keeping the internal details of a class or function hidden from the outside world.

• It is a fundamental principle of object-oriented programming.

• It helps in achieving encapsulation and abstraction.

• It prevents the user from accessing the internal workings of a class or function.

• Examples include private variables and methods in a class.

• It allows for easier maintenance and modification of code.

• It...read more