Username and Password Validation in React Example

This simple article demonstrates of react username and password validation. you can understand a concept of username and password validation in react js. this example will help you email and password validation in react. if you want to see example of react email and password validation then you are a right place.

Sometime we need to add username and password validation in react js then i will show you step by step how to add username validation without whitespace and minimum 6 character in react js.

in this example, we will create simple form with username, email, password and confirm password fields. then i will add validation for password and confirm password as bellow full example.

Let's follow bellow step and you will find preview as bellow:

Preview:

Step 1: Install React App

In our first step, we need to download react js fresh app using bellow command, if you didn't install yet then.

npx create-react-app my-app

Step 2: Create DemoForm Component

In this step, we will create DemoForm.js component file and we will write code of form validation. so let's add code as bellow:

src/DemoForm.js

import React from 'react';
  
class DemoForm extends React.Component {
    constructor() {
    super();
    this.state = {
      input: {},
      errors: {}
    };
     
    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  }
     
  handleChange(event) {
    let input = this.state.input;
    input[event.target.name] = event.target.value;
  
    this.setState({
      input
    });
  }
     
  handleSubmit(event) {
    event.preventDefault();
  
    if(this.validate()){
        console.log(this.state);
  
        let input = {};
        input["username"] = "";
        input["email"] = "";
        input["password"] = "";
        input["confirm_password"] = "";
        this.setState({input:input});
  
        alert('Demo Form is submitted');
    }
  }
  
  validate(){
      let input = this.state.input;
      let errors = {};
      let isValid = true;
   
      if (!input["username"]) {
        isValid = false;
        errors["username"] = "Please enter your username.";
      }
  
      if (typeof input["username"] !== "undefined") {
        const re = /^\S*$/;
        if(input["username"].length < 6 || !re.test(input["username"])){
            isValid = false;
            errors["username"] = "Please enter valid username.";
        }
      }
  
      if (!input["email"]) {
        isValid = false;
        errors["email"] = "Please enter your email Address.";
      }
  
      if (typeof input["email"] !== "undefined") {
          
        var pattern = new RegExp(/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i);
        if (!pattern.test(input["email"])) {
          isValid = false;
          errors["email"] = "Please enter valid email address.";
        }
      }
  
      if (!input["password"]) {
        isValid = false;
        errors["password"] = "Please enter your password.";
      }
  
      if (!input["confirm_password"]) {
        isValid = false;
        errors["confirm_password"] = "Please enter your confirm password.";
      }
  
      if (typeof input["password"] !== "undefined") {
        if(input["password"].length < 6){
            isValid = false;
            errors["password"] = "Please add at least 6 charachter.";
        }
      }
  
      if (typeof input["password"] !== "undefined" && typeof input["confirm_password"] !== "undefined") {
          
        if (input["password"] != input["confirm_password"]) {
          isValid = false;
          errors["password"] = "Passwords don't match.";
        }
      }
  
      this.setState({
        errors: errors
      });
  
      return isValid;
  }
     
  render() {
    return (
      <div>
        <h1>React Username and Password Validation Example - ItSolutionStuff.com</h1>
        <form onSubmit={this.handleSubmit}>
  
          <div class="form-group">
            <label for="username">Username:</label>
            <input 
              type="text" 
              name="username" 
              value={this.state.input.username}
              onChange={this.handleChange}
              class="form-control" 
              placeholder="Enter username" 
              id="username" />
  
              <div className="text-danger">{this.state.errors.username}</div>
          </div>
  
          <div class="form-group">
            <label for="email">Email Address:</label>
            <input 
              type="text" 
              name="email" 
              value={this.state.input.email}
              onChange={this.handleChange}
              class="form-control" 
              placeholder="Enter email" 
              id="email" />
  
              <div className="text-danger">{this.state.errors.email}</div>
          </div>
  
          <div class="form-group">
            <label for="password">Password:</label>
            <input 
              type="password" 
              name="password" 
              value={this.state.input.password}
              onChange={this.handleChange}
              class="form-control" 
              placeholder="Enter password" 
              id="password" />
  
              <div className="text-danger">{this.state.errors.password}</div>
          </div>
  
          <div class="form-group">
            <label for="password">Confirm Password:</label>
            <input 
              type="password" 
              name="confirm_password" 
              value={this.state.input.confirm_password}
              onChange={this.handleChange}
              class="form-control" 
              placeholder="Enter confirm password" 
              id="confirm_password" />
  
              <div className="text-danger">{this.state.errors.confirm_password}</div>
          </div>
             
          <input type="submit" value="Submit" class="btn btn-success" />
        </form>
      </div>
    );
  }
}
  
export default DemoForm;

Step 3: Import Component

In this step, we will import DemoFormcomponent in index.js main file. so let's update index.js file as bellow:

Here, i used bootstrap with react. so, if you want to use bootstrap in your app too then follow this tutorial: Install Bootstrap 4 in React JS.

src/index.js

import React from 'react';
import ReactDOM from 'react-dom';
import * as serviceWorker from './serviceWorker';
import 'bootstrap/dist/css/bootstrap.min.css';
  
import DemoForm from './DemoForm';
  
ReactDOM.render(
  <React.StrictMode>
    <div className="container">
       <DemoForm />
    </div>
  </React.StrictMode>,
  document.getElementById('root')
);
  
serviceWorker.unregister();

Now we are ready to run our application, so let's run using bellow command:

npm start

Open bellow url:

http://localhost:3000

I hope it can help you...