How to compared input to a list of safe input or characters when user submitting form by react js

Safe Input or Character 

Today in this blog, we will aware about How to remove array object elements in reactsjs. So, without wasting any time lets do it but lets recap what is exactly React js.

React

Certainly, Reactjs is a JavaScript library developed by Facenook for building user interfaces. It allows developers to create reusable UI components and effciently manage the state of their applications. Here are some key aspects of Reactjs.


Component-Based Architecture: ReactJS follows a component-based architecture, where the user interface is divided into small, reusable components. Components encapsulate their own logic, state, and rendering, making it easier to build and maintain complex user interfaces.



Virtual DOM: ReactJS uses a virtual representation of the DOM (Document Object Model), known as the Virtual DOM. When the state of a component changes, React updates the Virtual DOM.



JSX: JSX is a syntax extension for JavaScript used in React. It allows developers to write HTML-like code within JavaScript, making it easier to describe the structure and appearance of components. JSX code is transpiled to regular JavaScript using tools like Babel before being executed in the browser.


Hooks: React introduced Hooks in version 16.8 as a way to use state and other React features in functional components. Hooks allow developers to write reusable logic and manage state within functional components without the need for class components. The most commonly used hooks are useState for managing state and useEffect for handling side effects such as fetching data or subscribing to events.


React Router: React Router is a popular routing library for React applications. It enables developers to create single-page applications with multiple views and handles routing between different components based on the URL.


State Management: React provides a flexible ecosystem of state management solutions. While React's built-in state management (useState ) is suitable for managing local component state, more complex applications may benefit from additional state management libraries like Redux. These libraries help manage global application state and provide predictable ways to update and access the state.


ReactJS has gained widespread popularity due to its performance, reusability, and declarative approach to building user interfaces. It has large community.


NOTE - Here we will Tailwind CSS for designing.

In ReactJS, the user input can be compared to a list of safe characters or patterns by implementing input validation within the form component. React provides various ways to handle form inputs and validate user input. Here's an example of how you can do it:

Here we first make a file as called SafeInputForm.jsx.

import React, { useState } from 'react';

const SafeInputForm = () => {
  
  const safeCharacters = /^[a-zA-Z0-9]*$/;

 
  const [userInput, setUserInput] = useState('');
  const [errorMessage, setErrorMessage] = useState('');

  
  const handleSubmit = (event) => {
    event.preventDefault();

    // Check if the input is safe
    if (safeCharacters.test(userInput)) {
      
      alert('Input is valid!');
    } else {
     
      setErrorMessage('Invalid input! Please only use alphanumeric characters.');
    }
  };

 
  const handleInputChange = (event) => {
    
    setUserInput(event.target.value);
  };

  return (
    <form onSubmit={handleSubmit}>
      <label htmlFor="user_input">Enter your input:</label>
      <input
        type="text"
        name="user_input"
        id="user_input"
        value={userInput}
        onChange={handleInputChange}
      />
      <input type="submit" value="Submit" />
      {errorMessage && <p>{errorMessage}</p>}
    </form>
  );
};

export default SafeInputForm;

 
In this example, we define a regular expression safeCharacters that matches only alphanumeric characters. We use the useState hook to keep track of the user input and any error messages related to input validation.

The handleSubmit function is called when the form is submitted. It checks whether the user input matches the safeCharacters regular expression. If the input is valid, the form is processed (you can do additional actions like saving data to the server or performing some other task). If the input contains unsafe characters, an error message is displayed on the form.

The handleInputChange function is used to update the userInput state whenever the input field value changes.


In your main application file (app.jsx), you can include the SafeInputForm component, which will render the form on the page.


Output

if we dont enter alphanumeric character and using with space its generate error like invalid input, please only use alphanumeric characters.

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