Bolt IoT Front end Developer Interview Questions and Answers

SQL Server stored procedures and functions

• Stored procedures are precompiled SQL statements that can be executed with parameters

• Functions return a single value and can be used in SQL statements

• Both can improve performance and security by reducing network traffic and preventing SQL injection attacks

ASP.NET page life cycle is a series of events that occur when a page is requested, processed, and rendered.

• Page request is received by the server

• Page is initialized and controls are created

• Page is loaded with data and events are triggered

• Page is rendered and sent to the client

• Page is unloaded and disposed

Event bubbling is the process of propagating an event from the innermost element to its parent elements in the DOM hierarchy.

• Events in JavaScript are triggered on elements and then propagate up the DOM tree.

• During event bubbling, an event triggered on a child element will also trigger on its parent elements.

• This allows for event delegation, where a single event handler can be used for multiple elements.

• Event.stopPropag...read more

Redux is a predictable state container for JavaScript apps.

• Redux is a library for managing application state

• It provides a centralized store for all the state of an application

• It uses a single source of truth principle

• It allows for predictable state changes through actions and reducers

• It is commonly used with React for building complex UIs

jQuery is a fast, small, and feature-rich JavaScript library.

• jQuery simplifies HTML document traversing, event handling, and animating.

• It provides a set of methods for AJAX interactions and DOM manipulation.

• jQuery is cross-platform and supports a wide range of browsers.

• It has a large community and a vast number of plugins available.

• Project architecture depends on the specific project and its requirements.

Form validation in React ensures user input is correct before submission.

• Use controlled components to manage form state

• Create validation functions to check input

• Display error messages for invalid input

• Disable submit button until form is valid

• Consider using a library like Formik or Yup for easier validation

React hooks are functions that allow functional components to use state and lifecycle methods.

• Hooks were introduced in React 16.8

• useState() is a hook that allows state to be used in functional components

• useEffect() is a hook that allows lifecycle methods to be used in functional components

• Custom hooks can be created to reuse stateful logic across components