{"id":3917,"date":"2022-12-05T12:41:07","date_gmt":"2022-12-05T03:41:07","guid":{"rendered":"https:\/\/weseek.co.jp\/tech\/?p=3917"},"modified":"2023-04-17T10:25:43","modified_gmt":"2023-04-17T01:25:43","slug":"%e3%80%90react%e3%80%91usecallback%e3%81%ae%e9%81%a9%e5%88%87%e3%81%aa%e4%bd%bf%e3%81%84%e6%96%b9%e3%81%a8%e3%83%91%e3%83%95%e3%82%a9%e3%83%bc%e3%83%9e%e3%83%b3%e3%82%b9","status":"publish","type":"post","link":"https:\/\/weseek.co.jp\/tech\/3917\/","title":{"rendered":"\u3010React\u3011useCallback\u306e\u9069\u5207\u306a\u4f7f\u3044\u65b9\u3068\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9"},"content":{"rendered":"

\u306f\u3058\u3081\u306b<\/h2>\n

\u3053\u3093\u306b\u3061\u306f\u3001\u30b7\u30b9\u30c6\u30e0\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u86f8\u4e95\u3067\u3059\u3002
\n\u6700\u8fd1\u306f React \u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306b\u30cf\u30de\u3063\u3066\u304a\u308a\u3001\u3069\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u306e\u304c\u6700\u9069\u306a\u306e\u304b\u6c17\u306b\u306a\u3063\u305f\u305f\u3081\u8272\u3005\u3068\u8abf\u3079\u3066\u304d\u307e\u3057\u305f\u3002
\n\u4eca\u56de\u306e\u8a18\u4e8b\u3067\u306f\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306e\u4e2d\u3067\u3082 React Hooks \u306e useCallback \u306b\u7d5e\u3063\u3066\u3001\u9069\u5207\u306a\u4f7f\u3044\u65b9\u30fb\u4f7f\u3044\u6642\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n

<\/p>\n\n

useCallback \u3068\u306f<\/h2>\n

React Hooks \u306e useCallback \u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n

\u516c\u5f0f\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u8a18\u8f09\u3055\u308c\u3066\u3044\u307e\u3059\u3002
\nhttps:\/\/ja.reactjs.org\/docs\/hooks-reference.html#usecallback<\/a><\/p>\n

\n

\u30e1\u30e2\u5316\u3055\u308c\u305f\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u3092\u8fd4\u3057\u307e\u3059\u3002
\n\u30a4\u30f3\u30e9\u30a4\u30f3\u306e\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u3068\u305d\u308c\u304c\u4f9d\u5b58\u3057\u3066\u3044\u308b\u5024\u306e\u914d\u5217\u3092\u6e21\u3057\u3066\u304f\u3060\u3055\u3044\u3002useCallback \u306f\u305d\u306e\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u3092\u30e1\u30e2\u5316\u3057\u305f\u3082\u306e\u3092\u8fd4\u3057\u3001\u305d\u306e\u95a2\u6570\u306f\u4f9d\u5b58\u914d\u5217\u306e\u8981\u7d20\u306e\u3044\u305a\u308c\u304b\u304c\u5909\u5316\u3057\u305f\u5834\u5408\u306b\u306e\u307f\u5909\u5316\u3057\u307e\u3059\u3002\u3053\u308c\u306f\u3001\u4e0d\u5fc5\u8981\u306a\u30ec\u30f3\u30c0\u30fc\u3092\u907f\u3051\u308b\u305f\u3081\u306b\uff08\u4f8b\u3048\u3070 shouldComponentUpdate \u306a\u3069\u3092\u4f7f\u3063\u3066\uff09\u53c2\u7167\u306e\u540c\u4e00\u6027\u3092\u898b\u308b\u3088\u3046\u6700\u9069\u5316\u3055\u308c\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u3092\u6e21\u3059\u5834\u5408\u306b\u4fbf\u5229\u3067\u3059\u3002<\/p>\n<\/blockquote>\n

\u30e1\u30e2\u5316\u3068\u3044\u3046\u306e\u306f\u3001\u547c\u3073\u51fa\u3057\u306e\u7d50\u679c\u3092\u30ad\u30e3\u30c3\u30b7\u30e5\u3057\u3066\u304a\u304d\u3001\u518d\u5ea6\u540c\u3058\u5165\u529b\u304c\u767a\u751f\u3057\u305f\u3068\u304d\u306b\u30ad\u30e3\u30c3\u30b7\u30e5\u3092\u518d\u5229\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u518d\u8a08\u7b97\u3092\u9632\u3050\u3068\u3044\u3046\u624b\u6cd5\u3067\u3059\u3002
\n\u3064\u307e\u308a\u3001\u9069\u5207\u306b\u30e1\u30e2\u5316\u3092\u884c\u3046\u3053\u3068\u306b\u3088\u308a\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u901f\u5ea6\u3092\u5411\u4e0a\u3055\u305b\u3089\u308c\u307e\u3059\u3002<\/p>\n

useCallback \u306e\u69cb\u6587\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u3063\u3066\u304a\u308a\u3001<\/p>\n

useCallback(\u95a2\u6570, \u4f9d\u5b58\u914d\u5217)<\/code><\/pre>\n
\u5b9f\u969b\u306e\u66f8\u304d\u65b9\u306f\u3053\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
const memoizedCallback = React.useCallback(\n  () => {\n    doSomething(a, b);\n  },\n  [a, b]\n);<\/code><\/pre>\n
\u7b2c\u4e8c\u5f15\u6570\u306e [a, b]<\/code> \u306e\u90e8\u5206\u304c\u4f9d\u5b58\u914d\u5217\u3067\u3042\u308a\u3001\u3053\u306e\u914d\u5217\u306b\u683c\u7d0d\u3055\u308c\u305f\u8981\u7d20\u306e\u3044\u305a\u308c\u304b\u304c\u5909\u66f4\u3055\u308c\u305f\u3068\u304d\u306b\u95a2\u6570\u304c\u518d\u751f\u6210\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u4f9d\u5b58\u914d\u5217\u306e\u8981\u7d20\u306b\u5909\u66f4\u304c\u306a\u3051\u308c\u3070\u3001\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u305f\u3068\u3057\u3066\u3082\u3053\u306e useCallback \u306f\u540c\u3058\u95a2\u6570\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n
React.memo \u3068\u306f<\/h2>\n
\u6b21\u306e\u7ae0\u3067\u8a73\u3057\u304f\u8a71\u3057\u307e\u3059\u304c\u3001useCallback \u3068\u6df1\u304f\u304b\u304b\u308f\u3063\u3066\u3044\u308b React.memo \u306b\u3064\u3044\u3066\u3082\u8efd\u304f\u89e3\u8aac\u3057\u307e\u3059\u3002
\nReact.memo \u3068\u306f\u3001\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092\u30e1\u30e2\u5316\u3059\u308b\u95a2\u6570\u3067\u3059\u3002<\/p>\n
https:\/\/ja.reactjs.org\/docs\/react-api.html#reactmemo<\/a><\/p>\n
const MyComponent = React.memo((props) => {\n  \/* render using props *\/\n});<\/code><\/pre>\n
\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u7d50\u679c\u3092\u30ad\u30e3\u30c3\u30b7\u30e5\u3057\u3066\u304a\u304d\u3001\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u6e21\u3055\u308c\u305f props \u304c\u5909\u308f\u3089\u306a\u304b\u3063\u305f\u5834\u5408\u306b\u305d\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3092\u30b9\u30ad\u30c3\u30d7\u3057\u3001\u30ad\u30e3\u30c3\u30b7\u30e5\u3057\u305f\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u7d50\u679c\u3092\u518d\u5229\u7528\u3057\u307e\u3059\u3002<\/p>\n
\u3064\u307e\u308a\u89aa\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u305f\u3068\u304d\u306b\u3001React.memo \u5316\u3057\u305f\u5b50\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e props \u306b\u5909\u5316\u304c\u306a\u3051\u308c\u3070\u5b50\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3092\u30b9\u30ad\u30c3\u30d7\u3067\u304d\u308b\u305f\u3081\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u5411\u4e0a\u3057\u307e\u3059\u3002<\/p>\n
useCallback \u306f\u3069\u3046\u3044\u3046\u6642\u306b\u4f7f\u3046\u3079\u304d\u304b<\/h2>\n
\u7d50\u8ad6\u304b\u3089\u5148\u306b\u66f8\u304f\u3068\u3001useCallback \u306f\u57fa\u672c\u7684\u306b\u3001\u5148\u307b\u3069\u89e3\u8aac\u3057\u305f React.memo \u3068\u4f75\u7528\u3057\u3066\u4f7f\u3044\u307e\u3059\u3002
\nReact.memo \u5316\u3057\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u95a2\u6570\u3092\u6e21\u3059\u969b\u3001useCallback \u3067\u30e1\u30e2\u5316\u3057\u305f\u95a2\u6570\u3092\u6e21\u3059\u3053\u3068\u3067\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u5411\u4e0a\u3057\u307e\u3059\u3002<\/p>\n
\u516c\u5f0f\u306e useCallback \u306e\u8aac\u660e\u6587\u3092\u518d\u63b2\u3057\u307e\u3059\u3002
\nhttps:\/\/ja.reactjs.org\/docs\/hooks-reference.html#usecallback<\/a><\/p>\n
\n
\u3053\u308c\u306f\u3001\u4e0d\u5fc5\u8981\u306a\u30ec\u30f3\u30c0\u30fc\u3092\u907f\u3051\u308b\u305f\u3081\u306b\u53c2\u7167\u306e\u540c\u4e00\u6027\u3092\u898b\u308b\u3088\u3046\u6700\u9069\u5316\u3055\u308c\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u3092\u6e21\u3059\u5834\u5408\u306b\u4fbf\u5229\u3067\u3059\u3002<\/p>\n<\/blockquote>\n
useCallback \u3092\u4f7f\u3046\u4e00\u756a\u306e\u76ee\u7684\u306f \u4e0d\u8981\u306a\u30ec\u30f3\u30c0\u30fc\u3092\u907f\u3051\u308b\u305f\u3081<\/strong> \u3067\u3059\u3002
\n\u3061\u306a\u307f\u306b\u3053\u306e \u53c2\u7167\u306e\u540c\u4e00\u6027\u3092\u898b\u308b\u3088\u3046\u6700\u9069\u5316\u3055\u308c\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8<\/strong> \u3068\u3044\u3046\u306e\u304c React.memo \u5316\u3057\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
React.memo \u5316\u3057\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306f\u3001\u547c\u3073\u51fa\u3055\u308c\u305f\u6642\u306b props \u306b\u5909\u66f4\u304c\u306a\u3044\u304b\u30c1\u30a7\u30c3\u30af\u3092\u884c\u3044\u3001\u5909\u66f4\u304c\u306a\u304b\u3063\u305f\u6642\u306b\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3092\u30b9\u30ad\u30c3\u30d7\u3057\u307e\u3059\u3002<\/p>\n
\u3053\u3053\u3067\u91cd\u8981\u306b\u306a\u3063\u3066\u304f\u308b\u306e\u304c props \u306b\u5909\u66f4\u304c\u306a\u3044\u304b\u306e\u30c1\u30a7\u30c3\u30af\u306e\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n
React \u3067\u306f\u3001\u7b49\u4fa1\u6027\u306e\u6bd4\u8f03\u3092 Object.is<\/a> \u95a2\u6570\u306b\u3088\u308a\u884c\u3063\u3066\u3044\u307e\u3059\u3002(===<\/code> \u6f14\u7b97\u5b50\u3068\u3060\u3044\u305f\u3044\u540c\u3058)
\nReact.memo \u306e props \u306e\u6bd4\u8f03\u3060\u3051\u3067\u306a\u304f\u3001useEffect \u3084 useCallback, useMemo \u306e\u4f9d\u5b58\u914d\u5217\u306e\u6bd4\u8f03\u306a\u3069\u306b\u3082 Object.js \u304c\u4f7f\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
Object.is \u3067\u5024\u304c\u540c\u4e00\u3067\u3042\u308b\u304b\u3069\u3046\u304b\u3092\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3059\u304c\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3084\u914d\u5217\u3084\u95a2\u6570\u306a\u3069\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u578b\u306e\u3082\u306e (\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u3067\u306f\u306a\u3044\u3082\u306e) \u3092\u6bd4\u8f03\u3059\u308b\u5834\u5408\u3001\u305d\u306e\u5024\u305d\u306e\u3082\u306e\u3092\u6bd4\u8f03\u3059\u308b\u306e\u3067\u306f\u306a\u304f\u53c2\u7167\u5148\u306e\u60c5\u5831\u3092\u6bd4\u8f03\u3057\u307e\u3059\u3002
\n\u8a73\u3057\u304f\u306f \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u53c2\u7167\u3068\u30b3\u30d4\u30fc<\/a><\/p>\n
\u3064\u307e\u308a\u3001\u540c\u3058 key, value \u304c\u5165\u3063\u305f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3084\u540c\u3058\u5024\u304c\u5165\u3063\u305f\u914d\u5217\u3001\u540c\u3058\u30b3\u30fc\u30c9\u3067\u66f8\u304b\u308c\u305f\u95a2\u6570\u3067\u3042\u3063\u3066\u3082\u3001\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u524d\u3068\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u5f8c\u3067\u306f\u305d\u308c\u3089\u306f\u5b8c\u5168\u306b\u5225\u7269<\/strong>\u3068\u3057\u3066\u6271\u308f\u308c\u307e\u3059\u3002<\/p>\n
\u3053\u308c\u306b\u3088\u308a\u3069\u3046\u3044\u3063\u305f\u554f\u984c\u304c\u8d77\u3053\u308b\u306e\u304b\u3068\u3044\u3046\u3068\u3001React.memo \u5316\u3057\u305f\u5b50\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u578b\u306e\u3082\u306e (\u4eca\u56de\u306e\u4f8b\u3067\u306f\u95a2\u6570) \u3092\u6e21\u3057\u3066\u3044\u308b\u5834\u5408\u3001\u89aa\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u305f\u3068\u304d\u306b props \u304c\u5909\u308f\u3063\u305f\u3068\u307f\u306a\u3055\u308c\u3001\u5fc5\u305a\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u767a\u751f\u3057\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n
const ParentComponent = () => {\n  const sampleFunction = () => {}\n\n  return <ChildComponent sample={sampleFunction} >\n}\n\nconst ChildComponent = React.memo((props) => {\n  \/* \u7701\u7565 *\/\n});<\/code><\/pre>\n
\u3053\u306e\u3088\u3046\u306a\u30b1\u30fc\u30b9\u3067\u306f React.memo \u3092\u4f7f\u7528\u3057\u3066\u3044\u308b\u610f\u5473\u304c\u5168\u304f\u3042\u308a\u307e\u305b\u3093\u3002
\n\u3067\u306f\u3069\u3046\u3059\u308c\u3070\u826f\u3044\u306e\u304b\u3068\u3044\u3046\u3068\u3001useCallback \u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n
const ParentComponent = () => {\n  const sampleFunction = React.useCallback(() => {}, [])\n\n  return <ChildComponent sample={sampleFunction} >\n}\n\nconst ChildComponent = React.memo((props) => {\n  \/* \u7701\u7565 *\/\n});<\/code><\/pre>\n
useCallback \u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u3001\u4f9d\u5b58\u914d\u5217\u306e\u4e2d\u8eab\u304c\u5909\u308f\u3089\u306a\u304b\u3063\u305f\u5834\u5408\u30e1\u30e2\u5316\u3055\u308c\u305f\u95a2\u6570\u3001\u3064\u307e\u308a\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u524d\u3068\u540c\u4e00\u306e\u95a2\u6570\u304c\u8fd4\u308b\u305f\u3081\u3001\u3053\u306e\u95a2\u6570\u3092\u6e21\u3057\u3066\u3044\u308b\u5b50\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067 props \u304c\u5909\u5316\u3057\u3066\u3044\u306a\u3044\u3068\u307f\u306a\u3055\u308c\u3066\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u30b9\u30ad\u30c3\u30d7\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u3053\u308c\u304c\u3001\u3053\u306e\u7ae0\u3067\u6700\u521d\u306b\u8a18\u8f09\u3057\u305f useCallback \u306f\u57fa\u672c\u7684\u306b React.memo \u3068\u4f75\u7528\u3057\u3066\u4f7f\u3046<\/strong> \u3068\u3044\u3046\u7406\u7531\u3067\u3059\u3002<\/p>\n
\u305d\u306e\u4ed6\u306e\u4f7f\u3044\u65b9\u3068\u3057\u3066\u306f\u3001useEffect \u3084 useMemo, useCallback \u306a\u3069\u306e\u4f9d\u5b58\u914d\u5217\u306b\u95a2\u6570\u3092\u5165\u308c\u308b\u6642\u3067\u3059\u3002<\/p>\n
useEffect(() => {\n  doSomething()\n}, [doSomething])<\/code><\/pre>\n
\u4f9d\u5b58\u914d\u5217\u306b\u95a2\u6570\u3092\u5165\u308c\u308b\u5834\u5408\u3001useCallback \u3057\u305f\u95a2\u6570\u3092\u5165\u308c\u3066\u3042\u3052\u308b\u3068\u4e0d\u8981\u306a\u5b9f\u884c\u3092\u9632\u3052\u307e\u3059\u3002<\/p>\n
\u975e\u63a8\u5968\u3067\u3059\u304c\u3001useCallback \u305b\u305a\u306b\u305d\u3082\u305d\u3082\u4f9d\u5b58\u914d\u5217\u306b\u95a2\u6570\u3092\u6e21\u3055\u306a\u3044\u3068\u3044\u3046\u624b\u3082\u3042\u308a\u307e\u3059\u3002(eslint \u3092\u5c0e\u5165\u3057\u3066\u3044\u308b\u5834\u5408\u3001\u30eb\u30fc\u30eb\u306b\u3088\u3063\u3066\u306f\u8b66\u544a\u304c\u51fa\u305f\u308a\u3059\u308b)<\/p>\n
useEffect(() => {\n  doSomething()\n}, [])<\/code><\/pre>\n
useEffect \u306a\u3069\u306e\u5b9f\u884c\u306f\u3001\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3068\u6bd4\u8f03\u3057\u3066\u304b\u304b\u308b\u30b3\u30b9\u30c8\u304c\u975e\u5e38\u306b\u5c0f\u3055\u3044\u305f\u3081\u3001\u3053\u3053\u307e\u3067\u3057\u3066\u518d\u5b9f\u884c\u3092\u9632\u3050\u5fc5\u8981\u306f\u3042\u307e\u308a\u306a\u3044\u3068\u601d\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u3044\u305a\u308c\u306b\u305b\u3088\u3001\u4e0d\u8981\u306a\u30ec\u30f3\u30c0\u30fc\u3092\u9632\u3050\u3053\u3068\u304c useCallback \u3092\u4f7f\u7528\u3059\u308b\u4e00\u756a\u306e\u76ee\u7684\u3067\u3059\u3002<\/p>\n
\u3069\u3093\u306a\u6642\u3067\u3082\u4f7f\u3063\u3066\u826f\u3044\u306e\u304b<\/h2>\n
\u3053\u3053\u3067\u306f\u3001\u5358\u306b\u95a2\u6570\u81ea\u4f53\u306e\u518d\u751f\u6210\u3092\u9632\u3050\u76ee\u7684\u3067 useCallback \u3092\u4f7f\u7528\u3057\u3066\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u5411\u4e0a\u3059\u308b\u304b\u3069\u3046\u304b\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n
const MyComponent = () ={\n  const memoizedCallback = useCallback(\n    () => {\n      doSomething(a, b);\n    },\n    [a, b],\n  );\n\n  return (\n    \/* \u7701\u7565 *\/\n  )\n}<\/code><\/pre>\n
\u4e0a\u8a18\u306e\u4f8b\u306e\u5834\u5408\u3001MyComponent \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u308b\u305f\u3073\u306b useCallback \u304c\u547c\u3073\u51fa\u3055\u308c\u3001(\u4f9d\u5b58\u914d\u5217\u304c\u5909\u308f\u3089\u306a\u3051\u308c\u3070) memoizedCallback \u306b\u306f\u6bce\u56de\u540c\u3058\u95a2\u6570\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u683c\u7d0d\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u305f\u3060\u3057\u3001\u30ad\u30e3\u30c3\u30b7\u30e5\u3057\u305f\u7d50\u679c\u3092\u518d\u5229\u7528\u3059\u308b\u3068\u306f\u3044\u3048\u3001\u30a4\u30f3\u30e9\u30a4\u30f3\u95a2\u6570\u90e8\u5206\u306f\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u306e\u305f\u3073\u306b\u6bce\u56de\u4f5c\u6210\u3055\u308c\u307e\u3059\u3002<\/p>\n
() => {\n  doSomething(a, b);\n}<\/code><\/pre>\n
\u307e\u305f\u3001\u4f9d\u5b58\u914d\u5217\u306e\u4e2d\u8eab\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u4f5c\u696d\u3060\u3063\u305f\u308a\u3001\u30e1\u30e2\u5316\u3092\u3059\u308b\u3068\u3044\u3046\u51e6\u7406\u81ea\u4f53\u306b\u30b3\u30b9\u30c8\u304c\u304b\u304b\u308b\u305f\u3081\u3001\u4e0a\u8a18\u306e\u4f8b\u3067\u306f\u305d\u306e\u30b3\u30b9\u30c8\u306b\u898b\u5408\u3046\u3060\u3051\u306e\u52b9\u679c\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u305d\u306e\u305f\u3081\u7d50\u8ad6\u3068\u3057\u3066\u306f\u3001\u95a2\u6570\u81ea\u4f53\u306e\u518d\u751f\u6210\u3092\u9632\u3050\u76ee\u7684\u3067 useCallback \u3092\u4f7f\u7528\u3057\u3066\u3082\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u5411\u4e0a\u3059\u308b\u3053\u3068\u306f\u306a\u304f\u3001\u6c7a\u3057\u3066\u3069\u3093\u306a\u6642\u3067\u3082 useCallback \u3092\u4f7f\u7528\u3057\u3066\u826f\u3044\u3068\u306f\u8a00\u3048\u307e\u305b\u3093\u3002<\/p>\n
\u3053\u306e\u8a71\u306f\u4ee5\u4e0b\u306e\u30b5\u30a4\u30c8\u3067\u8a73\u3057\u304f\u89e3\u8aac\u3055\u308c\u3066\u3044\u307e\u3059\u3002
\nhttps:\/\/prateeksurana.me\/blog\/when-should-you-memoize-in-react\/#usecallback<\/a><\/p>\n
\u305d\u3082\u305d\u3082\u4f7f\u3044\u6642\u3092\u3057\u3063\u304b\u308a\u8003\u3048\u3066\u958b\u767a\u3059\u3079\u304d\u306a\u306e\u304b<\/h2>\n
\u5b9f\u969b\u306b\u8a08\u6e2c\u3057\u305f\u308f\u3051\u3067\u306f\u306a\u3044\u3067\u3059\u304c\u3001\u4f55\u3082\u8003\u3048\u305a\u306b useCallback \u3092\u4f7f\u7528\u3057\u305f\u5834\u5408\u3001\u304a\u305d\u3089\u304f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306f\u60aa\u5316\u3057\u307e\u3059\u3002
\n\u305f\u3060\u3057\u3053\u308c\u306b\u3088\u308b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u60aa\u5316\u306f\u672c\u5f53\u306b\u8aa4\u5dee\u30ec\u30d9\u30eb\u306a\u305f\u3081\u3001\u7279\u306b\u554f\u984c\u304c\u3042\u308b\u308f\u3051\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u3069\u3061\u3089\u304b\u3068\u3044\u3048\u3070\u3001\u30e1\u30e2\u5316\u7528\u306e\u95a2\u6570\u3067\u30e9\u30c3\u30d7\u3059\u308b\u5206\u30b3\u30fc\u30c9\u304c\u82e5\u5e72\u8907\u96d1\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u3053\u3068\u306e\u307b\u3046\u304c\u554f\u984c\u3067\u3042\u308b\u3068\u500b\u4eba\u7684\u306b\u601d\u3063\u3066\u307e\u3059\u3002<\/p>\n
React \u306f\u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u975e\u5e38\u306b\u9ad8\u901f\u3067\u52d5\u4f5c\u3059\u308b\u305f\u3081\u3001\u30e1\u30e2\u5316\u306b\u3088\u3063\u3066\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3092\u6570\u56de\u9632\u3044\u3060\u7a0b\u5ea6\u3067\u306f\u307b\u307c\u4f55\u3082\u5909\u308f\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u305f\u3044\u3066\u3044\u306e\u5834\u5408\u30e1\u30e2\u5316\u306b\u3088\u308b\u6700\u9069\u5316\u306f\u6c17\u306b\u3057\u306a\u304f\u3066\u3088\u304f\u3001\u3053\u306e\u3088\u3046\u306a\u6700\u9069\u5316\u3092\u3059\u308b\u3088\u308a\u3082\u4ed6\u306e\u3053\u3068\u306b\u6642\u9593\u3092\u5272\u304f\u3079\u304d\u3060\u3068\u3044\u3063\u305f\u58f0\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u304c\u91cd\u304f\u306a\u3063\u3066\u304d\u3066\u521d\u3081\u3066\u30e1\u30e2\u5316\u306b\u3088\u308b\u6700\u9069\u5316\u3092\u8003\u3048\u308b\u3001\u3068\u3044\u3063\u305f\u611f\u3058\u3067\u826f\u3044\u306e\u3067\u306f\u306a\u3044\u304b\u3068\u8003\u3048\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u3055\u3044\u3054\u306b<\/h2>\n
\u7d50\u8ad6\u3068\u3057\u3066\u306f\u3001\u4e0d\u8981\u306a\u30ec\u30f3\u30c0\u30fc\u3092\u9632\u3050\u3053\u3068\u304c useCallback \u3092\u4f7f\u7528\u3059\u308b\u4e00\u756a\u306e\u76ee\u7684\u3067\u3042\u308a\u3001useCallback \u306f React.memo \u5316\u3057\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u95a2\u6570\u3092\u6e21\u3059\u5834\u5408\u306b\u306e\u307f\u4f7f\u3048\u3070\u826f\u3044\u3053\u3068\u304c\u5206\u304b\u308a\u307e\u3057\u305f\u3002<\/p>\n
\u8abf\u3079\u3066\u3044\u304f\u4e2d\u3067\u3001\u305d\u3082\u305d\u3082\u3057\u3063\u304b\u308a\u3068\u3057\u305f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u3092\u884c\u3046\u5fc5\u8981\u306f\u306a\u3044\u3068\u3044\u3063\u305f\u58f0\u304c\u3061\u3089\u307b\u3089\u3042\u3063\u305f\u306e\u306f\u610f\u5916\u3067\u3057\u305f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u306f\u3058\u3081\u306b \u3053\u3093\u306b\u3061\u306f\u3001\u30b7\u30b9\u30c6\u30e0\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u86f8\u4e95\u3067\u3059\u3002 \u6700\u8fd1\u306f React \u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306b\u30cf\u30de\u3063\u3066\u304a\u308a\u3001\u3069\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u306e\u304c\u6700\u9069\u306a\u306e\u304b\u6c17\u306b\u306a\u3063\u305f\u305f\u3081\u8272\u3005\u3068\u8abf\u3079\u3066\u304d\u307e\u3057\u305f\u3002 \u4eca\u56de\u306e\u8a18\u4e8b\u3067\u306f\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3<\/p>\n","protected":false},"author":4,"featured_media":3599,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[31,51],"tags":[],"_links":{"self":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/3917"}],"collection":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/comments?post=3917"}],"version-history":[{"count":24,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/3917\/revisions"}],"predecessor-version":[{"id":4001,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/3917\/revisions\/4001"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/media\/3599"}],"wp:attachment":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/media?parent=3917"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/categories?post=3917"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/tags?post=3917"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}