Himalayan Bio Organic Foods Interview Questions and Answers

OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOP focuses on creating objects that interact with each other to solve complex problems

• Objects have attributes (data) and methods (functions) that operate on the data

• Encapsulation, inheritance, and polymorphism are key principles of OOP

• Example: A car object with attributes like color, model, and methods like start(), stop()

ArrayList is implemented as a resizable array, while LinkedList is implemented as a doubly linked list.

• ArrayList provides fast random access and slower insertion/deletion, while LinkedList provides fast insertion/deletion and slower random access.

• ArrayList uses less memory overhead compared to LinkedList.

• Example: ArrayList is more suitable for scenarios where random access is frequent, while LinkedList is more suitable for scenarios where frequent insertion/deletion is requir...read more

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• To retrieve a value, the key is hashed again to find the corresponding index and then the linked l...read more

Java Collection Framework is a set of classes and interfaces that provide various data structures and algorithms to store and manipulate collections of objects.

• Includes interfaces like List, Set, Queue, and classes like ArrayList, LinkedList, HashSet, PriorityQueue

• Provides implementations for common data structures like lists, sets, maps, queues, stacks

• Offers algorithms for searching, sorting, and manipulating collections

• Allows easy iteration and manipulation of collections u...read more

StringBuffer is synchronized and thread-safe, while StringBuilder is not synchronized and faster.

• StringBuffer is synchronized, meaning it is thread-safe and multiple threads can access it at the same time without any issues.

• StringBuilder is not synchronized, making it faster but not thread-safe. It is recommended for single-threaded operations.

• Use StringBuffer when working with multiple threads and synchronization is required. Use StringBuilder for better performance in singl...read more

Different ways to create strings in Java include using string literals, the new keyword, and the String class constructor.

• String literals: String str = "Hello World";

• Using new keyword: String str = new String("Hello World");

• String class constructor: char[] charArray = {'H', 'e', 'l', 'l', 'o'}; String str = new String(charArray);