Habilelabs Interview Questions and Answers

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...read more

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.

JavaScript counters can be incremented using various methods, including loops and functions, to track values over time.

• Use 'let count = 0;' to initialize a counter.

• Increment using 'count++;' or 'count += 1;'.

• Example: for (let i = 0; i < 5; i++) { count++; } results in count = 5.

• Functions can encapsulate counter logic: function increment() { count++; }.

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, compone...read more

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.

Props are read-only data passed from parent component to child component, while state is mutable data managed within a component.

• Props are used to pass data from parent to child components

• Props are read-only and cannot be modified by the child component

• State is used to manage mutable data within a component

• State can be updated using setState() method

• State should be used sparingly and only for data that affects the comp...read more