Habilelabs Interview Questions and Answers

hoc, pure component and react.memo are all ways to optimize React components.

• Higher Order Components (HOC) are functions that take a component and return a new component with additional functionality.

• Pure Components are components that only re-render when their props or state change.

• React.memo is a higher order component that memoizes the result of a component rendering, preventing unnecessary re-renders.

Closure is a function that has access to variables in its outer scope, even after the outer function has returned.

• Closure is created when a function is defined inside another function.

• The inner function has access to the outer function's variables and parameters.

• The inner function can access the outer function's variables even after the outer function has returned.

• Closures are used for data privacy, event handlers, and callbacks.

• Example: function outer() { let x = 10; functio...read more

A recursive function is a function that calls itself within its definition.

• A recursive function must have a base case to prevent infinite recursion.

• Recursion is often used to solve problems that can be broken down into smaller, similar subproblems.

• Example: Factorial function, Fibonacci sequence.

Oops concepts are the fundamental principles of object-oriented programming, including inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementation details and showing only the necessary featu...read more

To reverse a string, iterate through the characters and build a new string in reverse order.

• Iterate through the characters of the string from end to start

• Append each character to a new string to build the reversed string

• Return the reversed string as the result

Class components are based on ES6 classes and have lifecycle methods, while hooks are functions that allow state and other React features to be used in functional components.

• Class components have a render method, while functional components use a return statement.

• Hooks allow functional components to use state and lifecycle methods.

• Class components can have state and use lifecycle methods like componentDidMount, componentDidUpdate, and componentWillUnmount.

• Hooks like useState ...read more

C is a procedural programming language while C++ is an object-oriented programming language.

• C is a procedural programming language, while C++ is a combination of procedural and object-oriented programming.

• C does not support classes and objects, while C++ does.

• C does not have built-in support for exception handling, while C++ does.

• C does not have namespaces, while C++ does.

• C does not have function overloading, while C++ does.

Breaking UI into components is a process of dividing a UI into smaller, reusable parts.

• Identify the UI elements that can be reused

• Create separate components for each element

• Ensure each component is independent and can be used in different parts of the UI

• Use a component library to manage and reuse components

• Examples: buttons, forms, navigation bars, etc.