React Input Mask

<!DOCTYPE html>
<html>

<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState, useRef } = React;

function App() {
      const otpLength = 6; // You can change this to your desired OTP length
      const otpInputs = Array(otpLength).fill(null);
      const inputRefs = otpInputs.map(() => useRef(null));

const [otp, setOtp] = useState(new Array(otpLength).fill(''));

const handleInputChange = (e, index) => {
        const value = e.target.value;
        if (!/^\d*$/.test(value)) return; // Only allow numeric input

const newOtp = [...otp];
        newOtp[index] = value;
        setOtp(newOtp);

if (index < otpLength - 1 && value !== '') {
          inputRefs[index + 1].current.focus();
        }
      };

const handleBackspace = (e, index) => {
        if (e.key === 'Backspace' && index > 0 && otp[index] === '') {
          inputRefs[index - 1].current.focus();
        }
      };

return (
        <div className='container'>
          <h3>React Input Mask Google-style OTP</h3>
          <div className="otp-container">
            <span>G-</span>
            {otpInputs.map((_, index) => (
              <input
                key={index}
                type="text"
                maxLength="1"
                value={otp[index]}
                onChange={(e) => handleInputChange(e, index)}
                onKeyDown={(e) => handleBackspace(e, index)}
                ref={inputRefs[index]}
              />
            ))}
          </div>
        </div>
      );
    }

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

.otp-container {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 10px;
      font-size: 24px;
      width: 100%;
    }

/* Style individual input fields */
    .otp-container input {
      width: 40px;
      height: 40px;
      text-align: center;
      font-size: 24px;
      border: 2px solid #ccc;
      border-radius: 5px;
      outline: none;
      transition: border-color 0.2s;
    }

/* Style focused input field */
    .otp-container input:focus {
      border-color: #007bff;
      /* Change the border color when the input is focused */
    }

/* Style filled input field */
    .otp-container input:valid {
      border-color: #00cc00;
      /* Change the border color when the input is filled */
    }
  </style>
</body>

</html>