{"id":5726,"date":"2022-03-19T19:40:29","date_gmt":"2022-03-19T11:40:29","guid":{"rendered":"http:\/\/39.106.39.94\/?p=5726"},"modified":"2022-04-13T13:57:39","modified_gmt":"2022-04-13T05:57:39","slug":"%e6%b8%b2%e6%9f%93%e5%88%97%e8%a1%a8","status":"publish","type":"post","link":"https:\/\/lilichao.com\/?p=5726","title":{"rendered":"\u6e32\u67d3\u5217\u8868"},"content":{"rendered":"\n

\u73b0\u5728\uff0c\u6709\u8fd9\u6837\u4e00\u7ec4\u6570\u636e\uff0c\u9700\u8981\u5728\u9875\u9762\u4e2d\u5448\u73b0\uff1a<\/p>\n\n\n\n

const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];<\/pre>\n\n\n\n
\u5982\u679c\u60f3\u76f4\u63a5\u663e\u793a\uff0c\u53ef\u4ee5\u76f4\u63a5\u5c06\u6570\u7ec4\u63d2\u5165\u5230JSX\u4e2d\uff0cJSX\u4f1a\u81ea\u52a8\u5bf9\u6570\u7ec4\u5c55\u5f00\u5e76\u663e\u793a\u3002\u4f46\u8fd9\u6837\u4e00\u6765\u6570\u636e\u77e5\u8bc6\u76f4\u63a5\u663e\u793a\uff0c\u4e0d\u4f1a\u6dfb\u52a0\u4efb\u4f55\u7684\u7ed3\u6784\u3002\u5982\u679c\u5e0c\u671b\u5c06\u6570\u7ec4\u4e2d\u7684\u5143\u7d20\u653e\u5230\u4e00\u4e2a\u65e0\u5e8f\u5217\u8868\u4e2d\u663e\u793a\uff0c\u5c31\u9700\u8981\u5bf9\u5217\u8868\u505a\u4e00\u4e9b\u5904\u7406\u4e86\u3002<\/p>\n\n\n\n
<ul>
    <li>\u5b59\u609f\u7a7a<\/li>
    <li>\u732a\u516b\u6212<\/li>
    <li>\u6c99\u548c\u5c1a<\/li>
<\/ul><\/pre>\n\n\n\n
\u53ef\u4ee5\u4f7f\u7528for\u5faa\u73af\u5bf9\u5176\u8fdb\u884c\u5904\u7406\uff1a<\/p>\n\n\n\n
const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst items = [];\n\u200b\nfor(let i=0; i<students.length; i++){\n \u00a0 \u00a0items.push(<li>{stus[i]}<\/li>);\n}\n\u200b\nconst ele = <ul>{items}<\/ul><\/pre>\n\n\n\n
\u4e0a\u8fb9\u64cd\u4f5c\u7684\u672c\u8d28\u5176\u5b9e\u5c31\u662f\u6839\u636e\u4e00\u4e2a\u65e7\u6570\u7ec4students\u751f\u6210\u4e86\u4e00\u4e2a\u65b0\u6570\u7ec4items\uff1a<\/p>\n\n\n\n
const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst items = [\n \u00a0 \u00a0<li>\u5b59\u609f\u7a7a<\/li>,\n \u00a0 \u00a0<li>\u732a\u516b\u6212<\/li>,\n \u00a0 \u00a0<li>\u6c99\u548c\u5c1a<\/li>,\n];<\/pre>\n\n\n\n
\u8fd9\u4e2a\u64cd\u4f5c\u6211\u4eec\u4e5f\u53ef\u4ee5\u901a\u8fc7map()\u65b9\u6cd5\u6765\u5b8c\u6210\uff1a<\/p>\n\n\n\n
const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst items = students.map(item => <li>{item}<\/li>);\nconst ele = <ul>{items}<\/ul><\/pre>\n\n\n\n
map()\u672c\u8eab\u5c31\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u6240\u4ee5\u6211\u4eec\u5b8c\u5168\u53ef\u4ee5\u76f4\u63a5\u5c06\u51fd\u6570\u8c03\u7528\u5199\u5728JSX\u4e2d\u95f4\uff1a<\/p>\n\n\n\n
const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst ele = <ul>{students.map(item => <li>{item}<\/li>)}<\/ul><\/pre>\n\n\n\n
\u5f88\u663e\u7136\u4f7f\u7528map()\u6bd4\u4f7f\u7528for\u5faa\u73af\u8981\u4f18\u96c5\u5f88\u591a\uff0c\u6240\u4ee5\u8fd9\u4e5f\u662f\u6211\u4eec\u5728React\u4e2d\u7684\u5e38\u7528\u65b9\u5f0f\u3002<\/p>\n\n\n\n
\u8b66\u544a<\/h2>\n\n\n\n
\u8f93\u51fa\u4e00\u4e2a\u5217\u8868\u65f6\uff0c\u65e0\u8bba\u6211\u4eec\u4f7f\u7528\u7684for\u5faa\u73af\u8fd8\u662fmap()\u65b9\u6cd5\uff0c\u5f53\u4f60\u6253\u5f00\u63a7\u5236\u53f0\u65f6\u4f60\u4e00\u5b9a\u4f1a\u770b\u5230\u4e00\u884c\u7ea2\u8272\u7684\u5185\u5bb9\uff0c\u5b83\u5927\u6982\u5185\u5bb9\u662f\uff1aWarning: Each child in a list should have a unique “key” prop.<\/p>\n\n\n\n
Warning\u8868\u793a\u4e00\u4e2a\u8b66\u544a\uff0c\u8b66\u544a\u8868\u793a\u5b83\u5e76\u4e0d\u662f\u4e00\u4e2a\u7279\u522b\u4e25\u91cd\u7684\u9519\u8bef\uff0c\u4f46\u4f60\u6700\u597d\u628a\u5b83\u5904\u7406\u4e86\uff0c\u6240\u4ee5\u5f53\u4f60\u5728React\u9879\u76ee\u4e2d\u770b\u5230\u8fd9\u4e2a\u73a9\u610f\u7684\u65f6\u5019\u4e00\u5b9a\u4e00\u5b9a\u8981\u60f3\u529e\u6cd5\u53bb\u9664\u6389\u5b83\u3002<\/p>\n\n\n\n
\u4e3a\u4ec0\u4e48\u4f1a\u62a5\u51fa\u8fd9\u4e2a\u8b66\u544a\u5462\uff1f\u4e8b\u60c5\u8981\u5f80\u524d\u56de\u6eaf\u4e00\u4e0b\uff0c\u6211\u4eec\u5df2\u7ecf\u77e5\u9053React\u662f\u901a\u8fc7\u865a\u62dfDOM\u6765\u64cd\u4f5c\u5143\u7d20\u7684\uff0c\u800cReact\u4e3a\u4e86\u63d0\u5347\u64cd\u4f5c\u7684\u6027\u80fd\uff0c\u5728DOM\u53d1\u751f\u53d8\u5316\u65f6\u53ea\u4f1a\u53bb\u4fee\u6539\u90a3\u4e9b\u53d1\u751f\u4e86\u53d8\u5316\u7684\u5143\u7d20\uff0c\u8fd9\u6837\u5c31\u5927\u5927\u7684\u51cf\u5c11\u4e86DOM\u64cd\u4f5c\u4ece\u800c\u63d0\u5347\u4e86\u9875\u9762\u6e32\u67d3\u7684\u901f\u5ea6\u3002<\/p>\n\n\n\n
React\u600e\u4e48\u77e5\u9053\u54ea\u4e9b\u5143\u7d20\u53d1\u751f\u53d8\u5316\u5462\uff1f\u5176\u5b9e\u4e5f\u4e0d\u96be\uff0cReact\u6bcf\u6b21\u6e32\u67d3\u90fd\u4f1a\u751f\u6210\u4e00\u4e2a\u7531React\u5143\u7d20\u6784\u6210\u7684\u6811\uff08\u5f53\u7136\u8fd9\u68f5\u6811\u4e5f\u5bf9\u5e94\u7740\u4e00\u8bfeDOM\u5143\u7d20\u6784\u6210\u7684\u6811\uff0c\u4f46\u662f\u8fd9\u91cc\u4e0d\u592a\u91cd\u8981\uff09\uff0cReact\u6bcf\u6b21\u91cd\u65b0\u6e32\u67d3\u90fd\u4f1a\u751f\u6210\u4e00\u4e2a\u65b0\u7684React\u5143\u7d20\u6811\uff0c\u5728\u9875\u9762\u5237\u65b0\u524d\uff0cReact\u4f1a\u901a\u8fc7\u5185\u90e8\u7684diff\u7b97\u6cd5\u5bf9\u4e24\u4e2a\u6811\u4e2d\u7684React\u5143\u7d20\u8fdb\u884c\u6bd4\u8f83\uff0c\u5e76\u4e14\u627e\u5230\u90a3\u4e9b\u53d1\u751f\u53d8\u5316\u7684\u5143\u7d20\uff0c\u5e76\u5c06\u4ed6\u4eec\u7684\u53d8\u5316\u5728\u771f\u5b9e\u7684DOM\u5143\u7d20\u4e0a\u4f53\u73b0\u51fa\u6765\u3002<\/p>\n\n\n\n
\u8fd9\u4e2a\u7b97\u6cd5\u542c\u4e0a\u53bb\u5f88\u795e\u5947\uff0c\u5176\u5b9e\u5f88\u7b80\u5355\u5c31\u662f\u6309\u7167\u987a\u5e8f\u6bd4\u8f83\u4e24\u4e2a\u5143\u7d20\uff0c\u7b2c\u4e00\u4e2a\u548c\u7b2c\u4e00\u4e2a\u6bd4\uff0c\u7b2c\u4e8c\u4e2a\u548c\u7b2c\u4e8c\u4e2a\u6bd4\uff0c\u6ca1\u6709\u53d8\u5316\u5c31\u653e\u8fc7\uff0c\u6709\u53d8\u5316\u5c31\u8bb0\u5f55\u3002<\/p>\n\n\n\n
\u626f\u4e86\u8fd9\u4e48\u4e00\u957f\u4e32\uff0c\u548c\u4e0a\u8fb9\u7684\u8b66\u544a\u6709\u4ec0\u4e48\u5173\u7cfb\u5417\uff1f\u4e0a\u8fb9\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u628a\u4e00\u4e2a\u6570\u7ec4\u76f4\u63a5\u5728JSX\u4e2d\u5448\u73b0\u4e86\u51fa\u6765\u3002\u5f53\u6211\u4eec\u7b2c\u4e00\u6b21\u6e32\u67d3\u65f6\uff0c\u5217\u8868\u53ef\u80fd\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n\n\n\n
<ul>\n    <li>\u5b59\u609f\u7a7a<\/li>\n    <li>\u732a\u516b\u6212<\/li>\n    <li>\u6c99\u548c\u5c1a<\/li>\n<\/ul><\/pre>\n\n\n\n
\u5047\u4f7f\u6570\u7ec4\u53d1\u751f\u4e86\u53d8\u5316\uff08\u8fd9\u91cc\u8fd8\u6ca1\u8bb2\u600e\u4e48\u53d8\uff0c\u60f3\u8c61\u4e00\u4e0b\u5427\uff01\uff09\uff0c\u9875\u9762\u9700\u8981\u91cd\u65b0\u6e32\u67d3\uff0c\u53d8\u6210\u4e86\u8fd9\u6837\uff1a<\/p>\n\n\n\n
<ul>\n    <li>\u5b59\u609f\u7a7a<\/li>\n    <li>\u732a\u516b\u6212<\/li>\n    <li>\u6c99\u548c\u5c1a<\/li>\n    <li>\u5510\u50e7<\/li>\n<\/ul><\/pre>\n\n\n\n
\u8fd9\u91cc\u6211\u4eec\u5728\u5217\u8868\u7684\u6700\u540e\u589e\u52a0\u4e86\u4e00\u4e2a\u5510\u50e7\uff0c\u90a3\u4e48\u524d\u8fb9\u7684\u5143\u7d20\u987a\u5e8f\u662f\u4e0d\u53d8\u7684\uff0c\u5b59\u609f\u7a7a\u7b2c\u4e00\u4e2a\uff0c\u732a\u516b\u6212\u7b2c\u4e8c\uff0c\u6c99\u548c\u5c1a\u7b2c\u4e09\u3002\u6240\u4ee5\u8fd9\u91cc\u5728\u5e94\u7528\u4fee\u6539\u65f6\u53ea\u4f1a\u4fee\u6539\u6700\u540e\u4e00\u4e2ali\uff0c\u5bf9\u524d\u8fb9\u7684\u4e09\u4e2a\u4e0d\u4f1a\u6709\u4efb\u4f55\u5f71\u54cd\uff01\u6027\u80fd\u975e\u5e38\u68d2\uff01<\/p>\n\n\n\n
\u4f46\u662f\uff0c\u52a0\u5165\u5510\u50e7\u4e0d\u60f3\u5728\u6700\u540e\uff0c\u5b83\u60f3\u53bb\u7b2c\u4e00\u4e2a\u4f4d\u7f6e\uff0c\u50cf\u8fd9\u6837\uff1a<\/p>\n\n\n\n
<ul>\n    <li>\u5510\u50e7<\/li>\n    <li>\u5b59\u609f\u7a7a<\/li>\n    <li>\u732a\u516b\u6212<\/li>\n    <li>\u6c99\u548c\u5c1a<\/li>\n<\/ul><\/pre>\n\n\n\n
\u8fd9\u65f6\u95ee\u9898\u5c31\u6765\u4e86\uff0c\u5510\u50e7\u7b2c\u4e00\uff0c\u5b59\u609f\u7a7a\u7b2c\u4e8c…\u6362\u53e5\u8bdd\u8bf4\uff0c\u6240\u6709\u5143\u7d20\u7684\u987a\u5e8f\u90fd\u53d8\u4e86\uff0c\u90a3\u4e48React\u5728\u6bd4\u8f83\u5143\u7d20\u4e0d\u540c\u65f6\uff0c\u5b83\u5e76\u4e0d\u80fd\u77e5\u9053\u5b59\u609f\u7a7a\u4ece\u7b2c\u4e00\u53d8\u5230\u4e86\u7b2c\u4e8c\u4e2a\uff0c\u5b83\u4f1a\u4efb\u52a1\u662f\u5510\u50e7\u66ff\u6362\u4e86\u5b59\u609f\u7a7a\uff0c\u5b59\u609f\u7a7a\u66ff\u6362\u4e86\u732a\u516b\u6212\uff0c\u732a\u516b\u6212\u66ff\u6362\u4e86\u6c99\u548c\u5c1a\uff0c\u7136\u540e\u53c8\u589e\u52a0\u4e86\u4e00\u4e2a\u6c99\u548c\u5c1a\uff0c\u5bfc\u81f4\u9875\u9762\u6e32\u67d3\u662f\u56db\u4e2ali\u90fd\u88ab\u91cd\u65b0\u6e32\u67d3\u4e86\uff01\u5982\u679c\u5217\u8868\u91cc\u6709100\u4e2a\u5143\u7d20\uff0c\u90a3\u4e48\u5c31\u662f100\u4e2a\u90fd\u5f97\u91cd\u65b0\u6e32\u67d3\uff0c\u6027\u80fd\u4e0d\u597d\uff01<\/p>\n\n\n\n
\u90a3\u4e48\u8fd9\u79cd\u60c5\u51b5\uff0c\u6211\u4eec\u5c31\u9700\u8981\u8ba9React\u77e5\u9053\u8c01\u662f\u5b59\u609f\u7a7a\uff0c\u8c01\u53c8\u662f\u5510\u50e7\u3002\u5728React\u5185\u90e8\u5c31\u8bbe\u5b9a\u4e86\u4e00\u4e2akey\u5c5e\u6027\uff0ckey\u5c5e\u6027\u53ef\u4ee5\u4f5c\u4e3aReact\u5143\u7d20\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u548chtml\u4e2did\u7c7b\u4f3c\u3002\u5728\u521b\u5efa\u4e00\u4e2a\u5217\u8868\u65f6\uff0c\u6211\u4eec\u53ef\u4ee5\u4e3a\u5217\u8868\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\u6307\u5b9a\u4e00\u4e2a\u552f\u4e00\u7684key\uff0cReact\u5c31\u53ef\u4ee5\u6839\u636ekey\u800c\u4e0d\u662f\u4f4d\u7f6e\u6765\u6bd4\u8f83\u5143\u7d20\uff0c\u8fd9\u6837\u4e00\u6765\u65e0\u8bba\u5143\u7d20\u7684\u4f4d\u7f6e\u5982\u4f55\u6539\u53d8\uff0c\u90fd\u4e0d\u4f1a\u5bfc\u81f4\u8fc7\u591a\u7684\u5143\u7d20\u6e32\u67d3\uff0c\u56e0\u4e3a\u6709\u4e86key\u4ee5\u540e\uff0cReact\u5c31\u4e0d\u518d\u901a\u8fc7\u4f4d\u7f6e\u6765\u6bd4\u8f83\u4e24\u4e2a\u5143\u7d20\u4e86\u3002<\/p>\n\n\n\n
\u4e0a\u8fb9\u7684\u4f8b\u5b50\u53ef\u4ee5\u8fd9\u6837\u4fee\u6539\uff1a<\/p>\n\n\n\n
const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst ele = <ul>{students.map(item => <li key={item}>{item}<\/li>)}<\/ul><\/pre>\n\n\n\n
\u6dfb\u52a0\u4e86key\u5c5e\u6027\u4ee5\u540e\u8b66\u544a\u5c31\u6d88\u5931\u4e86\uff0c\u8bbe\u7f6ekey\u8fd8\u6709\u4e00\u4e9b\u8981\u6c42\uff1a<\/p>\n\n\n\n
  1. key\u5fc5\u987b\u5728\u5f53\u524d\u5217\u8868\u7684\u5143\u7d20\u4e2d\u662f\u552f\u4e00\u7684<\/li>
  2. \u4e00\u4e2a\u5143\u7d20\u7684key\u6700\u597d\u662f\u56fa\u5b9a\u7684<\/li><\/ol>\n\n\n\n
    key\u4e0d\u9700\u8981\u5168\u5c40\u552f\u4e00\uff0c\u53ea\u9700\u5728\u5f53\u524d\u5217\u8868\u4e2d\u552f\u4e00\u5373\u53ef\u3002\u5143\u7d20\u7684key\u6700\u597d\u662f\u56fa\u5b9a\u7684\uff0c\u8fd9\u91cc\u76f4\u63a5\u4e3e\u4e2a\u53cd\u4f8b\uff0c\u6709\u4e9b\u573a\u666f\u6211\u4eec\u4f1a\u4f7f\u7528\u5143\u7d20\u7684\u7d22\u5f15\u4e3akey\u50cf\u8fd9\u79cd\uff1a<\/p>\n\n\n\n
    const students = ['\u5b59\u609f\u7a7a', '\u732a\u516b\u6212', '\u6c99\u548c\u5c1a'];\nconst ele = <ul>{students.map((item, index) => <li key={index}>{item}<\/li>)}<\/ul><\/pre>\n\n\n\n
    \u4e0a\u4f8b\u4e2d\uff0c\u6211\u4f7f\u7528\u4e86\u5143\u7d20\u7684\u7d22\u5f15\uff08index\uff09\u4f5c\u4e3akey\u6765\u4f7f\u7528\uff0c\u4f46\u8fd9\u6709\u4ec0\u4e48\u7528\u5417\uff1f\u6ca1\u7528\uff01\u56e0\u4e3aindex\u662f\u6839\u636e\u5143\u7d20\u4f4d\u7f6e\u7684\u6539\u53d8\u800c\u6539\u53d8\u7684\uff0c\u5f53\u6211\u4eec\u5728\u524d\u8fb9\u63d2\u5165\u4e00\u4e2a\u65b0\u5143\u7d20\u65f6\uff0c\u6240\u6709\u5143\u7d20\u7684\u987a\u5e8f\u90fd\u4f1a\u4e00\u8d77\u6539\u53d8\uff0c\u90a3\u4e48\u5b83\u548cReact\u4e2d\u6309\u987a\u5e8f\u6bd4\u8f83\u6709\u4ec0\u4e48\u533a\u522b\u5417\uff1f\u6ca1\u6709\u533a\u522b\uff01\u800c\u4e14\u8fd8\u9ebb\u70e6\u4e86\uff0c\u552f\u4e00\u7684\u4f5c\u7528\u5c31\u662f\u53bb\u9664\u4e86\u8b66\u544a\u3002\u6240\u4ee5\u6211\u4eec\u5f00\u53d1\u7684\u65f6\u5019\u5076\u5c14\u4e5f\u4f1a\u4f7f\u7528\u7d22\u5f15\u4f5c\u4e3akey\uff0c\u4f46\u524d\u63d0\u662f\u5143\u7d20\u7684\u987a\u5e8f\u4e0d\u4f1a\u53d1\u751f\u53d8\u5316\uff0c\u9664\u6b64\u4e4b\u5916\u4e0d\u8981\u7528\u7d22\u5f15\u505akey\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u73b0\u5728\uff0c\u6709\u8fd9\u6837\u4e00\u7ec4\u6570\u636e\uff0c\u9700\u8981\u5728\u9875\u9762\u4e2d\u5448\u73b0\uff1a const students = [‘\u5b59\u609f\u7a7a’, ‘\u732a\u516b\u6212’, ‘\u6c99 […]<\/p>\n","protected":false},"author":1,"featured_media":5728,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[198],"tags":[200,202,219,199],"_links":{"self":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/5726"}],"collection":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5726"}],"version-history":[{"count":2,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/5726\/revisions"}],"predecessor-version":[{"id":5729,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/5726\/revisions\/5729"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/media\/5728"}],"wp:attachment":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5726"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5726"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5726"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}