Recrosoft Technologies Developer Interview Questions and Answers

Hooks are functions that allow you to use state and other React features without writing a class.

• Hooks were introduced in React 16.8

• They allow you to reuse stateful logic

• useState is a hook that allows you to add state to a functional component

• useEffect is a hook that allows you to perform side effects in a functional component

• useContext is a hook that allows you to consume a context in a functional component

useMemo is used to memoize a value while useCallback is used to memoize a function.

• useMemo is used to optimize expensive computations by caching the result and returning it if the inputs are the same.

• useCallback is used to optimize expensive function creation by caching the function and returning it if the inputs are the same.

• useMemo returns a value while useCallback returns a memoized function.

• useMemo is used for memo...read more

Call, apply, and bind are methods used to manipulate the value of 'this' in JavaScript functions.

• Call and apply are used to invoke a function with a specific 'this' value and arguments passed as an array or list respectively.

• Bind returns a new function with a specific 'this' value and any arguments passed as a list.

• Example: myFunction.call(thisValue, arg1, arg2); myFunction.apply(thisValue, [arg1, arg2]); myFunction.bi...read more

The CSS box model is a design concept that describes how elements are displayed on a web page.

• It consists of content, padding, border, and margin.

• The content is the actual element and its size is determined by width and height properties.

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

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

• Margin is the space between the border and the next element.

• The box mo...read more

Closures are functions that have access to variables in their outer scope, even after the outer function has returned.

• Closures are created when a function is defined inside another function.

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

• Closures can be used to create private variables and methods in JavaScript.

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