Hearzap Interview Questions and Answers

I am a Full Stack Developer with a passion for creating innovative web applications and solving complex problems.

• Experienced in both front-end and back-end development

• Proficient in languages such as JavaScript, HTML, CSS, and frameworks like React and Node.js

• Strong problem-solving skills and ability to work in a team environment

• Previous projects include e-commerce websites, social media platforms, and data visualizatio...read more

Flattened LinkedList combines multiple linked lists into a single sorted linked list.

• A flattened linked list is a multi-level linked list where each node may point to another linked list.

• Example: Node 1 -> Node 2 -> Node 3; Node 2 points to Node 4 -> Node 5.

• To flatten, traverse each node and merge the linked lists into one.

• Use a priority queue to maintain order while merging nodes from different lists.

JavaScript hoisting is a behavior where variable and function declarations are moved to the top of their containing scope during compilation.

• Hoisting applies to variable declarations (using var) and function declarations.

• Variables declared with 'let' and 'const' are hoisted but not initialized.

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

• Function declarations are hoisted completely: greet(); function greet(...read more

React Hooks are a feature that allows functional components to have state and lifecycle methods.

• useState is used to manage state in functional components

• useEffect is used to perform side effects in functional components

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

• useEffect example: useEffect(() => { console.log('Component did mount') }, [])

Virtual DOM is a lightweight copy of the actual DOM, used for efficient updates in web development.

• Virtual DOM is a concept used in frameworks like React to improve performance by minimizing actual DOM manipulations.

• When changes are made to the Virtual DOM, it is compared to the actual DOM and only the differences are updated.

• This process reduces the number of expensive DOM operations, resulting in faster rendering and...read more

To balance the parentheses in a stack, use a stack data structure to keep track of opening and closing parentheses.

• Use a stack to push opening parentheses and pop when encountering a closing parenthesis

• Check if the stack is empty at the end to ensure all parentheses are balanced

useEffect is a hook in React that allows you to perform side effects in function components.

• useEffect is used to perform side effects in function components

• It takes two arguments: a function and an optional array of dependencies

• The function inside useEffect will run after every render, unless specified otherwise in the dependencies array

• Common use cases include fetching data, subscribing to events, and updating the DOM

PUT is used to update or replace an entire resource, while PATCH is used to update or modify a part of a resource.

• PUT is idempotent, meaning multiple identical requests will have the same effect as a single request

• PATCH is not idempotent, meaning multiple identical requests may have different effects

• PUT requires the client to send the entire updated resource, while PATCH only requires the client to send the specific ch...read more

I am a full stack developer with experience in front-end and back-end technologies.

• Proficient in HTML, CSS, JavaScript, Node.js, and React

• Skilled in database management with SQL and MongoDB

• Experience with version control systems like Git

• Strong problem-solving and communication skills