ReactJS：TypeError：无法读取null的属性“值”

Question

我正在关注关于React Hooks的ReactJS教程。我试图从用户那里获取并显示输入名称，但是键入两个字符后，我的应用程序崩溃，错误为“ TypeError：无法读取null的属性'value'”

import React, { useState } from 'react';

    function HookCounterTwo(props) {
        const initialName = {
            firstName: '',
            lastName: ''
        };
        const [name, setName] = useState(initialName);

        const changename = (e) => {
            setName(prevName=>({...prevName, firstName: e.target.value}));
        }

        return (
            <div>
            {name.firstName}
                <input type='text' value={name.firstName} onChange={e=>changename(e)} />
            </div>
        );
    }

    export default HookCounterTwo;

以下是日志：

HookCounterTwo.js:11 Uncaught TypeError: Cannot read property 'value' of null
    at HookCounterTwo.js:11
    at basicStateReducer (react-dom.development.js:15013)
    at updateReducer (react-dom.development.js:15135)
    at updateState (react-dom.development.js:15237)
    at Object.useState (react-dom.development.js:15949)
    at useState (react.development.js:1497)
    at HookCounterTwo (HookCounterTwo.js:8)
    at renderWithHooks (react-dom.development.js:14803)
    at updateFunctionComponent (react-dom.development.js:17034)
    at beginWork (react-dom.development.js:18610)
    at HTMLUnknownElement.callCallback (react-dom.development.js:188)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:237)
    at invokeGuardedCallback (react-dom.development.js:292)
    at beginWork$1 (react-dom.development.js:23203)
    at performUnitOfWork (react-dom.development.js:22154)
    at workLoopSync (react-dom.development.js:22130)
    at performSyncWorkOnRoot (react-dom.development.js:21756)
    at react-dom.development.js:11089
    at unstable_runWithPriority (scheduler.development.js:653)
    at runWithPriority$1 (react-dom.development.js:11039)
    at flushSyncCallbackQueueImpl (react-dom.development.js:11084)
    at flushSyncCallbackQueue (react-dom.development.js:11072)
    at flushPendingDiscreteUpdates (react-dom.development.js:21847)
    at flushDiscreteUpdates (react-dom.development.js:21827)
    at finishEventHandler (react-dom.development.js:764)
    at batchedEventUpdates (react-dom.development.js:798)
    at dispatchEventForLegacyPluginEventSystem (react-dom.development.js:3568)
    at attemptToDispatchEvent (react-dom.development.js:4267)
    at dispatchEvent (react-dom.development.js:4189)
    at unstable_runWithPriority (scheduler.development.js:653)
    at runWithPriority$1 (react-dom.development.js:11039)
    at discreteUpdates$1 (react-dom.development.js:21887)
    at discreteUpdates (react-dom.development.js:806)
    at dispatchDiscreteEvent (react-dom.development.js:4168)

我刚开始使用React，所以我可能会缺少一些概念。谢谢