Aloha Technology Software Developer Interview Questions and Answers

Abstract class is a class that cannot be instantiated and is used as a blueprint for other classes.

• Abstract class can have abstract methods that must be implemented by its subclasses.

• Real life example of abstraction is a vehicle class with abstract methods like start() and stop().

• Subclasses like Car and Bike can implement these abstract methods in their own way.

Check if a number is divisible by 2 using modulo operator.

• Use the modulo operator (%) to check if the remainder is 0 when dividing the number by 2.

• If the remainder is 0, then the number is divisible by 2.

• For example, if num % 2 == 0, then the number is divisible by 2.

To find palindrome words in a sentence, split the sentence into words and check if each word is equal to its reverse.

• Split the sentence into words using whitespace as a delimiter

• Iterate through each word and check if it is equal to its reverse

• If a word is a palindrome, add it to the list of palindrome words

• Consider case-insensitivity while checking for palindromes

Code to print prime numbers in a given range

• Iterate through numbers in the range and check if each number is prime

• Use a nested loop to check divisibility of each number by numbers less than itself

• Print the number if it is prime

Access modifiers are keywords in programming languages that define the accessibility of classes, methods, and variables.

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

• Public access allows classes, methods, and variables to be accessed from any other class.

• Private access restricts access to only within the same class.

• Protected access allows access within the same package or subclasses.

• Default access allows access only within the same...read more

Classes are blueprints for creating objects in object-oriented programming. Objects are instances of classes.

• Classes define the properties and behaviors of objects.

• Objects are instances of classes that can hold data and perform actions.

• Classes can inherit properties and behaviors from other classes.

• Objects can interact with each other by calling methods or accessing properties.

• Example: Class 'Car' can have properties like 'color' and 'speed', and objects of class 'Car' can be...read more

OOPs is a programming paradigm based on the concept of objects that interact with each other.

• OOPs stands for Object-Oriented Programming.

• It focuses on the creation of objects that have properties and methods.

• Encapsulation, Inheritance, Polymorphism, and Abstraction are the four main pillars of OOPs.

• Design patterns are reusable solutions to common software problems.

• Some popular design patterns are Singleton, Factory, Observer, and Decorator.

Object-oriented programming concepts can be applied to databases for better organization and efficiency.

• Encapsulation: Data and methods are encapsulated within classes to ensure data integrity.

• Inheritance: Tables can inherit properties and methods from other tables, reducing redundancy.

• Polymorphism: Different tables can have different implementations of the same method.

• Abstraction: Complex database structures can be abstracted into simpler, more manageable entities.