React Js for Web Development > Components

Understanding Index.js

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The indexOf() method returns the position of a value in a string's first occurrence. If the value cannot be retrieved, the indexOf() method returns -1.

Reordering an item alters the index if the key is an index. As a result, the component state may become jumbled, and the old key may be used for a different component instance. React can't tell if an element was removed or merely the content was updated without a unique key.

indexOf returns the first index in the array where a specified element can be found, or -1 if it does not exist. So index is simply the counter's index in counters. You're making a comparison between an object (counter) and a number ( index ).

  • The indexOf() method is used for a single-dimensional array of primitive datatypes such as string, number, and so on.
  • When looking for an index value from an object element, the findIndex() method is used.

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Course Content

  1. About Course
    4m 35s
  2. What is React
    4m 5s
  3. Single Page Application
    3m 12s
  4. Why Choose React for Web Development?
    6m 30s
  5. Real Time Example
    3m 46s
  6. React VS Angular VS vue
    7m 7s
  7. Setting up the first project
    13m 22s

  1. Components in React
    10m 37s
  2. How to Create Components in React
    7m 14s
  3. Installation of Node
    7m 57s
  4. Creating the First Project
    8m 41s
  5. Understanding File Structure
    10m 3s
  6. Understanding Index.js
    9m 38s
  7. Introduction to JSX
    8m 32s
  8. Custom Components
    9m 5s
  9. Assignmnet : Introduction
    3m 48s
  10. Assignment : Components
    3m 47s

  1. Adding Template in JSX React
    4m 19s
  2. Adding Styles in JSX React
    7m 34s
  3. Dynamic Data in JSX React
    8m 46s
  4. Data Passing in React
    11m 16s
  5. Accessing Props in React
    8m 40s
  6. Implementing JS Code in JSX React
    9m 21s
  7. Creating Single Responsibility Components in React
    16m 54s
  8. Children Props in React
    14m 40s
  9. Other Details in JSX React
    14m 16s
  10. Assignment : JSX
    4m

  1. Event Listening in React
    8m 16s
  2. Event Handling in React
    11m 13s
  3. States in React
    17m
  4. Adding Forms in React
    9m 59s
  5. Feching Form Inputs in React
    18m 7s
  6. Storing Form Inputs in React
    8m 56s
  7. Another Method for Storing Form Inputs in React
    20m 52s
  8. Submitting Forms in React
    8m 57s
  9. Two Way Binding in React
    6m 19s
  10. Component Communication in React
    7m 27s
  11. Adding Custom Components in React
    10m 40s
  12. Lifting State up in React
    4m 3s
  13. Filter Component in React
    17m 14s
  14. Updating States in React
    9m 3s
  15. Controlled vs Uncontrolled Components in React
    11m 50s
  16. Assignment : Events
    5m 13s

  1. Iterating the List in JSX React
    14m
  2. Arrays in React State
    19m
  3. Filtering the Data in React
    8m 55s
  4. Conditional Rendering in React
    13m 31s
  5. Handling Conditions in React
    8m 24s
  6. Conditional Return in React
    15m 13s
  7. Adding Handlers in React part -1
    8m 31s
  8. Adding Handlers in React part -2
    21m 36s
  9. Charts in React
    16m 58s
  10. Adding Dynamic Style Sheets in React
    10m 31s
  11. Creating Dataset in React
    11m 12s
  12. Calculating Max Value in Charts
    11m 3s
  13. Global CSS in React
    6m 8s
  14. Assignment : Iterations and conditions
    4m 13s

  1. Styling in React
    7m 9s
  2. Dynamic Styling
    14m 56s
  3. Dynamic Classes
    10m 42s
  4. CSS Scope in React
    11m 18s
  5. Styled Components in React
    21m 13s
  6. Responsive Styling in React
    9m 28s
  7. Style Module in React
    6m 58s
  8. Adding Media Queries in React
    9m 38s
  9. Assignment : Styling
    4m 21s

  1. Handling Syntax Errors in React
    17m 43s
  2. Debugging in React
    13m 50s
  3. Developer Tools in React
    13m 7s
  4. Assignment : Error and Debugging
    3m 2s

  1. Creating Application in React
    18m 29s
  2. Container Component
    7m 59s
  3. Adding Styles to Inputs
    7m 13s
  4. Reusable Component
    11m 9s
  5. Managing Data in React
    11m 38s
  6. Resetting & Validating Form Data in React
    15m 42s
  7. Adding Data to List in React
    12m 36s
  8. Adding State to List in React
    13m 21s
  9. Adding Modal in React
    15m 11s
  10. Error Boundaries in React
    13m 26s
  11. Assignment : Dialogs and Modals
    4m 4s

  1. Limitations of JSX
    10m 7s
  2. Wrapper Component in React
    4m 28s
  3. Fragments in React
    7m 25s
  4. Portals in React
    27m 33s
  5. React Refs
    20m 45s
  6. Uncontrolled Inputs in React
    7m 1s
  7. Assignment : Fragments and portals
    4m 27s

  1. Effect Hooks in React Part-1
    12m 7s
  2. Effect Hooks in React Part-2
    11m
  3. Local Storage With React Hooks
    15m 34s
  4. UseEffect Hook in React
    10m 22s
  5. Adding React Dependencies
    25m 5s
  6. Adding Delays in React
    11m 6s
  7. Cleartimeout Function in React
    14m 5s
  8. Reducer in React
    12m 23s
  9. Usereducer() Hook in React
    11m 40s
  10. Replacing State in React
    25m 12s
  11. useReducer With useEffect in React
    13m 2s
  12. useReducer vs useState
    8m 46s
  13. Introduction to React Context
    14m 58s
  14. Adding Context in React
    12m 39s
  15. Providing React Context
    7m 54s
  16. Listening React Context
    12m 34s
  17. React useContext Hook
    6m 11s
  18. Passing Function
    15m 54s
  19. React Context Provider
    13m 25s
  20. limitations of React Context
    6m 43s
  21. React Hooks
    10m 31s
  22. TagInput in React
    12m 59s
  23. Using ForwardRef in React
    12m 56s
  24. Assignments: Effects, Reducer & Context
    2m 50s

  1. React: The Virtual DOM
    21m 42s
  2. Re-evaluation of React Component
    12m 41s
  3. React Memo Hook
    9m 54s
  4. Primitive Values vs Objects in React
    5m 38s
  5. React useCallback
    7m 58s
  6. useCallback Dependency Array
    13m 9s
  7. React State Scheduling
    9m 10s
  8. React State Batching
    8m 25s
  9. useMemo in React
    18m 17s
  10. Types of Components
    7m 59s
  11. Class Based Components
    13m 24s
  12. States in Class Based Components
    5m 40s
  13. Events in Class Based Components
    18m 41s
  14. React Component Lifecycle
    26m 1s
  15. React Context with Class Based
    19m 4s
  16. Class Components vs Functional Components in React
    9m 23s
  17. Error Boundaries in React
    27m 55s
  18. Assignment : Class Based Components
    3m 35s

  1. Database Connection in React
    10m 12s
  2. Backend Application in React
    12m 8s
  3. Data Fetching in React
    9m 41s
  4. Handling Response in React
    10m 5s
  5. React Async
    9m 21s
  6. Handling Loaders in React
    11m 10s
  7. Handling No Data in React
    7m 35s
  8. Structure of HTTP Request in React
    10m 35s
  9. React Error Codes
    12m 18s
  10. Handling Errors in React
    14m 39s
  11. useeffect() & UseCallback() in React
    11m 57s
  12. Storing the Data in React
    16m 21s
  13. Try and Catch Block in React
    7m 4s
  14. Transforming Response in React
    16m 47s
  15. Assignment : HTTP Module
    2m 29s

  1. React Custom Hooks
    7m 1s
  2. Why to use Custom Hooks
    4m 22s
  3. Creating Custom Hooks
    13m 27s
  4. Implementing Custom Hooks in React
    16m 4s
  5. Configuring React Custom Hooks
    9m 49s
  6. Custom Hook With HTTP
    17m 3s
  7. Adding Parameteres in Custom Hooks
    7m 22s
  8. Calling React Custom Hooks
    23m 47s
  9. Using callback() with Custom Hooks
    2m 30s
  10. Adjusting Parameters in Custom Hooks
    7m 16s
  11. React Forms
    10m 1s
  12. Checking Validity in React Forms
    6m 34s
  13. Creating Simple Form in React
    17m 25s
  14. Add Validations on React Forms
    11m 40s
  15. Handling Touch Property in React
    11m 22s
  16. Handling Blur Property in React
    8m 5s
  17. Input Validity Check in React Forms
    15m 50s
  18. Validity in React Forms
    7m 39s
  19. Adding Multiple Inputs in React Forms
    15m 33s
  20. Adding Custom Hook in React Forms
    8m 1s
  21. Generalizing Input Hooks
    8m 4s
  22. Using React Hooks in Component
    10m 50s
  23. Using Reducer in React
    13m 45s
  24. Assignment : Custom Hooks and Forms
    3m 50s

  1. Introduction to Redux
    13m 31s
  2. Redux vs Context API
    7m 50s
  3. How Redux Works
    7m 48s
  4. Understanding Redux in detail
    12m 7s
  5. Handling Actions in Reducer Function
    10m 47s
  6. Installing Redux with React
    5m 45s
  7. Creating store
    11m 8s
  8. Providing Store
    7m 40s
  9. Subscribing Data in Component
    12m 27s
  10. Dispatching Actions in Component
    11m 32s
  11. Handling Multiple Properties in Redux
    17m 3s
  12. Challenges in Redux
    8m 21s
  13. Redux Toolkit
    13m 22s
  14. Handling Redux States
    6m 26s
  15. Defining Actions in Redux
    8m 13s
  16. Routing
    10m 2s
  17. Installing React Router
    8m 44s
  18. Defining Routes
    14m 44s
  19. Navigation
    5m 6s
  20. React Router Link
    5m 33s
  21. NavLink & activeClass Name in React
    4m 15s
  22. Dynamic Routes in React
    9m 13s
  23. Switch and Nested Routes
    21m 57s
  24. Redirect Component
    7m 28s
  25. 404 Page Not Found in React
    6m 5s
  26. Assignment : Redux
    3m 53s

  1. Authentication in React
    7m 21s
  2. How Authentication Works
    8m 40s
  3. Types of Authentication
    8m 41s
  4. Firebase Authentication in React
    8m 1s
  5. Sign up Page in React
    12m 53s
  6. Handling Warning Messages
    7m 37s
  7. Firebase Authentication for Login Page
    9m
  8. Adding Authentication Context
    16m 59s
  9. Implementing Authentication Context
    4m 39s
  10. Handling Protected Resources
    9m 29s
  11. Password Reset Form in React
    9m 23s
  12. Improvising User Experience
    5m 1s
  13. Logout in React
    12m 38s

  1. Course Summary
    4m 47s

  1. Interview Questions in React js
    29m 13s

  1. Career Guideline
    2m 40s
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