Alpha Design Technologies System Engineer Hardware Interview Questions and Answers

The life cycle of a servlet includes initialization, service, and destruction.

• Servlet is initialized by calling its init() method

• Servlet handles client requests in its service() method

• Servlet is destroyed by calling its destroy() method

• Examples of servlet containers include Tomcat and Jetty

init() method initializes an object or a class.

• init() method is used to initialize an object or a class.

• It is called automatically when an object is created.

• It can be used to set default values for object properties.

• It can also be used to perform any necessary setup operations.

• Example: __init__() method in Python.

• Example: init() method in Java.

• Example: viewDidLoad() method in iOS development.

Servlets are used for server-side processing and JSP for presentation. Both have their own advantages.

• Servlets are used for handling complex business logic and database operations.

• JSP is used for presentation and displaying dynamic content.

• Servlets are faster than JSP as they do not involve the overhead of rendering HTML.

• Servlets can be used to handle multiple requests simultaneously.

• JSP can be used for rapid developme...read more

StringBuilder and StringBuffer are classes in Java used for manipulating strings.

• StringBuilder is faster and not thread-safe while StringBuffer is slower but thread-safe.

• Both classes provide methods for appending, inserting, and deleting characters in a string.

• StringBuilder and StringBuffer are mutable, meaning the original string can be modified.

• Example: StringBuilder sb = new StringBuilder("Hello"); sb.append(" World...read more

Referential integrity constant ensures that a foreign key value always refers to an existing primary key value.

• It maintains consistency between related tables

• It prevents orphaned records

• It enforces data integrity

• Example: A foreign key in the Orders table refers to the primary key in the Customers table

Code for infinite loop and prime number check

• For infinite loop: while(1) { //code }

• For prime number check: bool isPrime(int n) { for(int i=2; i<=sqrt(n); i++) { if(n%i == 0) return false; } return true; }

• Infinite loop can be used for continuous monitoring or background tasks

• Prime number check is useful in cryptography and number theory

OOPS principles are a set of guidelines that help in creating modular, reusable, and maintainable code.

• Encapsulation: Hiding the implementation details of an object and exposing only the necessary information.

• Inheritance: Creating new classes from existing ones, inheriting their properties and methods.

• Polymorphism: The ability of objects to take on multiple forms or behaviors.

• Abstraction: Focusing on the essential feat...read more

Java OOPS is class-based and strongly typed, while Python OOPS is dynamic and duck-typed.

• Java OOPS requires explicit declaration of data types, while Python OOPS does not.

• Java OOPS has strict rules for inheritance and polymorphism, while Python OOPS allows for more flexibility.

• Java OOPS has a more verbose syntax, while Python OOPS is more concise and readable.

• Example: Java - public class Car extends Vehicle; Python - c