Interview Questions and Answers

Program to separate odd and even numbers from an array.

• Loop through array and check if each number is odd or even

• Create two separate arrays for odd and even numbers

• Return both arrays

Design a database schema for a food delivery app

• Create tables for users, restaurants, orders, and menu items

• Use foreign keys to establish relationships between tables

• Include columns for user details, restaurant details, order details, and menu item details

• Consider adding tables for reviews, ratings, and payment information

Java platform independence refers to the ability of Java code to run on any device or operating system without modification.

• Java code is compiled into bytecode, which can be executed on any device with a Java Virtual Machine (JVM)

• JVM acts as an abstraction layer between the Java code and the underlying hardware and operating system

• This allows Java programs to be written once and run anywhere, making them platform independent

Use SQL query with subquery to find second highest salary

• Use subquery to find the max salary first

• Then use another subquery to find the max salary excluding the previously found max salary

Java is platform-independent, object-oriented, and has automatic memory management. C++ is faster, closer to hardware, and allows more control over memory management.

• Java is platform-independent, while C++ is platform-dependent.

• Java is object-oriented, while C++ supports both procedural and object-oriented programming.

• Java has automatic memory management (garbage collection), while C++ requires manual memory management.

• C++ is faster than Java due to its closer-to-hardware nat...read more

Access modifiers control the visibility and accessibility of classes, methods, and variables in object-oriented programming.

• Access modifiers include public, private, protected, and default (package-private)

• Public: accessible from any other class

• Private: only accessible within the same class

• Protected: accessible within the same package and subclasses

• Default: accessible within the same package

Inheritance in Java allows a class to inherit properties and behaviors from another class.

• Inheritance is achieved using the 'extends' keyword in Java.

• Subclasses can access the methods and fields of the superclass.

• Java does not support multiple inheritance, but a class can implement multiple interfaces.

LRU Cache is a data structure that stores the most recently used items, discarding the least recently used items when full.

• Use a combination of a doubly linked list and a hashmap to efficiently implement LRU Cache.

• When an item is accessed, move it to the front of the linked list to mark it as the most recently used.

• When the cache is full, remove the least recently used item from the end of the linked list and the hashmap.