React Js Validate a Bitcoin Address

<!DOCTYPE html>
<html>

return (
        <div className='container'>
          <h3 className='heading'>React Js Bitcoin Address Validator</h3>
          <input
            type="text"
            className='input-field'
            placeholder="Enter a Bitcoin address"
            value={address}
            onChange={(e) => setAddress(e.target.value)}
          />
          <button className='validate-button' onClick={validateAddress}>
            Validate Address
          </button>
          {isMessageVisible && (
            <p className='message'>
              {isValid
                ? <span style={{ color: 'green' }}>The Bitcoin address is valid.</span>
                : <span style={{ color: 'red' }}>The Bitcoin address is not valid.</span>
              }
            </p>
          )}

</div>

);

}
    ReactDOM.render(<App />, document.getElementById("app"));
  </script>

.container {
      margin: 0 auto;
      width: 600px;
      text-align: center;
      box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);
      padding: 20px;
    }

heading {
      font-size: 24px;
      margin-bottom: 20px;
      color: #333;
    }

.input-field {
      padding: 10px;
      width: 300px;
      border: 1px solid #ccc;
      border-radius: 5px;
      font-size: 16px;
      margin-bottom: 10px;
      outline: none;
    }

.validate-button {
      padding: 10px 20px;
      background-color: #007BFF;
      color: #fff;
      border: none;
      border-radius: 5px;
      cursor: pointer;
      font-size: 18px;
      transition: background-color 0.3s;
    }

.validate-button:hover {
      background-color: #0056b3;
    }

.message {
      font-size: 18px;
      margin-top: 20px;
      color: #007BFF;
    }
  </style>
</body>

</html>

 
<!DOCTYPE html>
<html>
​
<head>
  <meta charset="UTF-8" />
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
​
<body>
  <div id="app"></div>
​
  <script type="text/babel">
    const { useState } = React;
    function App() {
      const [address, setAddress] = useState('1Lbcfr7sAHTD9CgdQo3HTMTkV8LK4ZnX71');
      const [isValid, setIsValid] = useState(false);
      const [isMessageVisible, setMessageVisible] = useState(false);
​
      const validateAddress = () => {
        const regEx = /^[13][a-km-zA-HJ-NP-Z1-9]{25,34}$/;
        if (regEx.test(address)) {
          setIsValid(true);
        } else {
          setIsValid(false);
        }
        // Show the message when validation is performed
        setMessageVisible(true);
      };
​
      return (
        <div className='container'>
          <h3 className='heading'>React Js Bitcoin Address Validator</h3>
          <input
            type="text"
            className='input-field'
            placeholder="Enter a Bitcoin address"
            value={address}
            onChange={(e) => setAddress(e.target.value)}
          />
          <button className='validate-button' onClick={validateAddress}>
            Validate Address
          </button>
          {isMessageVisible && (
            <p className='message'>
              {isValid
                ? <span style={{ color: 'green' }}>The Bitcoin address is valid.</span>
                : <span style={{ color: 'red' }}>The Bitcoin address is not valid.</span>
              }
            </p>
          )}
​
        </div>
​
      );
​
    }
    ReactDOM.render(<App />, document.getElementById("app"));
  </script>
​
  <style>
    * {
      box-sizing: border-box;
    }
​
    .container {
      margin: 0 auto;
      width: 600px;
      text-align: center;
      box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);
      padding: 20px;
    }
​
    heading {
      font-size: 24px;
      margin-bottom: 20px;
      color: #333;
    }
​
    .input-field {
      padding: 10px;
      width: 300px;
      border: 1px solid #ccc;
      border-radius: 5px;
      font-size: 16px;
      margin-bottom: 10px;
      outline: none;
    }
​
    .validate-button {
      padding: 10px 20px;
      background-color: #007BFF;
      color: #fff;
      border: none;
      border-radius: 5px;
      cursor: pointer;
      font-size: 18px;
      transition: background-color 0.3s;
    }
​
    .validate-button:hover {
      background-color: #0056b3;
    }
​
    .message {
      font-size: 18px;
      margin-top: 20px;
      color: #007BFF;
    }
  </style>
</body>
​
</html>