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rakesh kumar
rakesh kumar

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Explain the terminology useContext and useAppContext in react js

React provides a feature called "Context" that allows you to share data between components without passing props explicitly through every level of the component tree. Context is often used when you have data that needs to be accessible by multiple components at different levels of the tree.

To access the context data in a functional component, you can use the useContext hook provided by React. This hook takes the context object as an argument and returns the current value of the context.

Here's an example of how you can create and use a context in React:

import React, { createContext, useContext } from 'react';

// Create a context
const MyContext = createContext();

// Create a component that provides the context value
const MyContextProvider = ({ children }) => {
  const contextValue = 'Hello from context';

  return (
    <MyContext.Provider value={contextValue}>
      {children}
    </MyContext.Provider>
  );
};

// A child component that consumes the context value
const ChildComponent = () => {
  const contextValue = useContext(MyContext);

  return <div>{contextValue}</div>;
};

// App component
const App = () => {
  return (
    <MyContextProvider>
      <ChildComponent />
    </MyContextProvider>
  );
};
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In this example, the MyContextProvider component is responsible for providing the context value, which is 'Hello from context'. The ChildComponent uses the useContext hook to access and consume that value

Difference between useAppContext and useContext in react js

The useAppContext and useContext hooks in React.js serve similar purposes but have different implementations and use cases.

useContext:
The useContext hook is a built-in hook provided by React that allows functional components to access the value of a context. It takes the context object as an argument and returns the current value of the context.
Here's an example using useContext:

import React, { createContext, useContext } from 'react';

// Create a context
const ThemeContext = createContext();

// A component that provides the context value
const App = () => {
  const theme = 'light';

  return (
    <ThemeContext.Provider value={theme}>
      <Toolbar />
    </ThemeContext.Provider>
  );
};

// A child component that consumes the context value
const Toolbar = () => {
  const theme = useContext(ThemeContext);

  return (
    <div>
      <Button theme={theme} />
    </div>
  );
};
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In this example, the Toolbar component uses useContext(ThemeContext) to access the value of the ThemeContext context provided by the App component. It retrieves the current value (theme) and passes it as a prop to the Button component.

useAppContext:
The useAppContext hook, as mentioned in your previous question, is not a built-in hook provided by React. It is likely a custom hook specific to your application or a third-party library. The purpose and implementation of useAppContext can vary depending on its specific usage.
Here's a hypothetical example demonstrating a custom useAppContext hook:

import React, { createContext, useContext } from 'react';

// Create a context
const AppContext = createContext();

// A custom hook to access the app context value
const useAppContext = () => {
  return useContext(AppContext);
};

// A component that provides the context value
const App = () => {
  const appData = {
    username: 'John',
    age: 25,
  };

  return (
    <AppContext.Provider value={appData}>
      <Profile />
    </AppContext.Provider>
  );
};

// A child component that consumes the context value using the custom hook
const Profile = () => {
  const appData = useAppContext();

  return (
    <div>
      <h1>{appData.username}</h1>
      <p>Age: {appData.age}</p>
    </div>
  );
};
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In this example, we define a custom hook useAppContext that encapsulates the usage of useContext(AppContext). The AppContext is a context created using createContext, and the App component provides the context value (appData).

The Profile component uses the custom useAppContext hook to access the context value. It retrieves the appData object containing the username and age and renders them in the JSX.

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