30+ Hackmakers Interview Questions and Answers

A linked list is a linear data structure where each element is a separate object with a pointer to the next element.

• Linkedlist allows for efficient insertion and deletion of elements

• It can be used to implement stacks, queues, and graphs

• Traversal is slower compared to arrays

• Examples include singly linked list, doubly linked list, and circular linked list

Hoisting is a JavaScript mechanism where variables and function declarations are moved to the top of their scope.

• Hoisting applies to variable declarations and function declarations

• Variables are initialized with undefined and functions are fully defined

• Hoisting only moves the declarations, not the assignments

• Example: console.log(x); var x = 5; // Output: undefined

• Closure is a function that has access to its outer function's variables, even after the outer function has returned...read more

This could refer to anything in javascript, please provide more context.

• Please provide more context for a specific answer.

• It could be a variable, function, object, or any other javascript construct.

• Without more information, it is impossible to provide a specific answer.

Box model is a way of representing HTML elements as rectangular boxes with content, padding, border, and margin.

• The box model consists of content, padding, border, and margin.

• Content is the actual content of the element.

• Padding is the space between the content and the border.

• Border is the line that surrounds the padding and content.

• Margin is the space between the border and other elements.

• To center an input tag, set margin-left and margin-right to auto and display to block.

useState is a hook in React that allows functional components to have state variables.

• useState is a built-in hook in React.

• It allows functional components to have state variables.

• It takes an initial state value and returns an array with the current state value and a function to update it.

• The state can be updated using the function returned by useState.

• Example: const [count, setCount] = useState(0);

Temporal dead zone is a behavior in JavaScript where a variable cannot be accessed before it is declared.

• Variables declared with let and const are hoisted but cannot be accessed before their declaration

• Trying to access a variable in its temporal dead zone results in a ReferenceError

• Temporal dead zone is a feature introduced in ES6 to improve JavaScript's scoping mechanism

I will designate a quiet, well-lit area in my home for work, with a comfortable chair and desk setup.

• Designate a specific area in your home for work to create a separation between work and personal life.

• Ensure the area is well-lit and free from distractions to maintain focus.

• Invest in a comfortable chair and desk setup to promote good posture and reduce physical strain.

• Organize the space with necessary office supplies and equipment for efficiency.

• Establish a routine and bound...read more

Interview questions for full stack intern position

• 1) Comfortable language - Java

• 2) Call by reference - passing memory address, call by value - passing value

• 3) Java is not pure object oriented as it supports primitive data types

• 4) Pointers are not used in Java

• 5) Constructor is a special method used to initialize objects

• 6) Java program example: public class Main { public static void main(String[] args) { System.out.println("Hello World!"); }}

To select a box using Selenium, we can use the findElement() method with appropriate locator strategies.

• Identify the element using a unique locator such as ID, name, class name, etc.

• Use the findElement() method to locate the element on the web page.

• Perform actions on the element using various methods such as click(), sendKeys(), etc.

• Example: WebElement checkbox = driver.findElement(By.id("checkbox_id")); checkbox.click();

Data types in JavaScript include primitive and object types.

• Primitive types include string, number, boolean, null, undefined, and symbol.

• Object types include arrays, functions, and objects.

• Typeof operator can be used to determine the type of a variable.

• Type coercion can occur when different types are used together.

Client service is for businesses while customer service is for individuals.

• Client service is focused on building and maintaining relationships with businesses that use the company's products or services.

• Customer service is focused on providing support and assistance to individual customers who have purchased the company's products or services.

• Client service often involves more personalized attention and may include things like account management and strategic planning.

• Custome...read more

Javascript is a scripting language used for web development, while Java is a general-purpose programming language.

• Javascript is interpreted, while Java is compiled

• Javascript is used for client-side scripting, while Java is used for server-side programming

• Javascript is loosely typed, while Java is strongly typed

• Javascript has a prototype-based object model, while Java has a class-based object model

React Vdom is a virtual representation of the actual DOM used by React to optimize rendering performance.

• Vdom is a lightweight copy of the actual DOM tree.

• React compares the previous and current Vdom trees to determine the minimum number of changes required to update the actual DOM.

• This approach reduces the number of DOM manipulations and improves performance.

• Vdom can be created using React.createElement() or JSX syntax.

Test cases for login functionality excluding correct and incorrect username and password.

• Test for login with blank username and password fields

• Test for login with valid username and blank password field

• Test for login with blank username and valid password field

• Test for login with invalid username and valid password field

• Test for login with valid username and invalid password field

• Test for login with special characters in username and password fields

• Test for login with long us...read more

Frontend is the client-side of an application that users interact with, while backend is the server-side that manages data and logic.

• Frontend is responsible for the user interface and user experience.

• Backend is responsible for server-side logic, database operations, and authentication.

• Frontend technologies include HTML, CSS, and JavaScript, while backend technologies include Node.js, Python, and Java.

• Examples of frontend frameworks are React, Angular, and Vue, while examples ...read more

Locators in Selenium are used to identify web elements on a web page.

• Locators are used to find web elements based on their attributes like ID, class, name, etc.

• Some commonly used locators in Selenium are ID, Name, Class Name, Tag Name, Link Text, and Partial Link Text.

• For example, driver.findElement(By.id("username")) will find the element with ID attribute as "username".

Full stack development refers to the practice of developing both the front-end and back-end of a website or application.

• Full stack developers are proficient in both front-end technologies like HTML, CSS, and JavaScript, as well as back-end technologies like Node.js, Python, or Java.

• They are able to work on all aspects of a project, from designing user interfaces to managing databases and servers.

• Examples of full stack development frameworks include MEAN (MongoDB, Express.js, ...read more

Assertion in Selenium is a command that verifies if the expected result matches the actual result of a test step.

• Assertions are used to validate the behavior of a web application under test.

• They help in identifying defects early in the development cycle.

• Selenium provides various assertion methods like assertEquals, assertTrue, assertFalse, etc.

• If the assertion fails, the test case is marked as failed and the execution stops.

• Assertions can be used in combination with condition...read more

Schema design for a stack overflow website

• Use tables for users, questions, answers, comments, votes, tags

• Establish relationships between tables (e.g. user_id in questions table)

• Include fields like title, body, created_at, updated_at, etc.

• Implement features like upvoting, downvoting, tagging, commenting

• Consider indexing for faster search and retrieval

Software development life cycle is a process used by software developers to design, develop, test, and deploy software applications.

• It consists of several phases such as planning, analysis, design, implementation, testing, and maintenance.

• Each phase has its own set of activities and deliverables.

• Examples of software development life cycle models include Waterfall, Agile, and DevOps.

Java supports various data types including primitive and reference types.

• Primitive data types: int, double, char, boolean, etc.

• Reference data types: String, Arrays, Classes, Interfaces, etc.

• Examples: int num = 10; String name = "John"; char grade = 'A';

Trending topics in AI include natural language processing, computer vision, and ethical AI.

• Natural language processing advancements for improved chatbots and virtual assistants

• Computer vision technologies for object recognition and autonomous vehicles

• Ethical AI discussions around bias, transparency, and accountability

• AI applications in healthcare for diagnosis and personalized treatment

Removing duplicates without using inbuilt methods in JavaScript

• Create an empty array to store unique values

• Loop through the original array

• Check if the current element exists in the unique array

• If not, push it to the unique array

• Return the unique array

Unit testing in Java is a software testing method where individual units or components of a software are tested in isolation.

• Unit testing helps in identifying bugs early in the development process.

• JUnit is a popular unit testing framework for Java.

• Mockito is used for mocking dependencies in unit tests.

• Unit tests should be fast, isolated, and repeatable.

• Example: @Test annotation in JUnit is used to mark a method as a unit test.

OOPs concepts are the fundamental principles of object-oriented programming.

• Encapsulation - binding data and functions together

• Inheritance - acquiring properties and behavior of parent class

• Polymorphism - ability to take multiple forms

• Abstraction - hiding implementation details

• Example: A car is an object that encapsulates data like speed and functions like accelerate and brake

• Example: A child class inherits properties and behavior from a parent class

• Example: A function can ta...read more

Data types are classifications of data items that specify the type of value it can hold.

• Data types define the operations that can be performed on the data

• Examples include integers, strings, booleans, arrays, and objects

• Each programming language has its own set of data types

A program to sort numbers in an array

• Use a sorting algorithm like bubble sort, selection sort, or quicksort

• Iterate through the array and compare each element to sort them

• Ensure the program handles edge cases like empty arrays or arrays with only one element

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

• Inheritance promotes code reusability by allowing a new class to use the properties and methods of an existing class.

• The class that is being inherited from is called the superclass or parent class, while the class that inherits is called the subclass or child class.

• Subclasses can add their own unique properties and methods, as well as override inherited methods.

• Example: class Dog ...read more