解决React报错`value` prop on `input` should not be null

export default function App() {
  // ⛔️ Warning: `value` prop on `input` should not be null.
  // Consider using an empty string to clear the component or `undefined` for uncontrolled components.
  return (
    <div>
      <input value={null} />
    </div>
  );
}

import {useState} from 'react';
const App = () => {
  // 👇️ pass empty string as initial value
  const [message, setMessage] = useState('');
  const handleChange = event => {
    setMessage(event.target.value);
  };
  // ✅ use fallback, e.g.
  //  value={message || ''}
  return (
    <div>
      <input
        type="text"
        id="message"
        name="message"
        onChange={handleChange}
        value={message || ''}
      />
    </div>
  );
};
export default App;

import {useRef} from 'react';
const App = () => {
  const inputRef = useRef(null);
  function handleClick() {
    console.log(inputRef.current.value);
  }
  return (
    <div>
      <input
        ref={inputRef}
        type="text"
        id="message"
        name="message"
        defaultValue="Initial value"
      />
      <button onClick={handleClick}>Log message</button>
    </div>
  );
};
export default App;