{"id":33628,"date":"2023-01-12T16:55:58","date_gmt":"2023-01-12T07:55:58","guid":{"rendered":"https:\/\/laboradian.com\/?p=33628"},"modified":"2023-01-19T14:16:01","modified_gmt":"2023-01-19T05:16:01","slug":"create-weak-reference-in-javascript","status":"publish","type":"post","link":"https:\/\/laboradian.com\/create-weak-reference-in-javascript\/","title":{"rendered":"JavaScript \u3067\u300c\u5f31\u3044\u53c2\u7167\u300d\u3092\u4f5c\u6210\u3059\u308b"},"content":{"rendered":"\n

1. \u300c\uff08\u666e\u901a\u306e\uff09\u53c2\u7167\u300d\u3068\u300c\u5f31\u3044\u53c2\u7167\u300d<\/h2>\n\n\n\n

\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3001{ name; 'foo' }<\/code> \u3068\u3044\u3046\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c obj<\/code> \u3068\u3044\u3046\u5909\u6570\u306b\u30bb\u30c3\u30c8\u3055\u308c\u305f\u5834\u5408\u3001\u3053\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306f obj<\/code> \u3068\u3044\u3046\u5909\u6570\u306b\u3088\u3063\u3066\u300c\u53c2\u7167<\/strong>\u300d\u3055\u308c\u3066\u3044\u308b\u3068\u8a00\u3048\u307e\u3059\u3002<\/p>\n\n\n\n

let obj = { name: 'foo' }<\/code><\/pre>\n\n\n\n
\u3053\u306e\u3088\u3046\u306b\u3001\u3042\u308b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3078\u306e\u300c\uff08\u666e\u901a\u306e\uff09\u53c2\u7167<\/strong>\u300d\u304c\u5b58\u5728\u3057\u3066\u3044\u308b\u9593\u3001\u305d\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u30e1\u30e2\u30ea\u4e0a\u304b\u3089\u52dd\u624b\u306b\u524a\u9664\u3055\u308c\u308b\u3053\u3068\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u307e\u3060\u305d\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306f\u4f7f\u308f\u308c\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u306e\u3067\u3002\u5f53\u305f\u308a\u524d\u306e\u8a71\u3067\u306f\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n
\u3057\u304b\u3057\u3001\u3053\u306e\u5f8c \u3053\u306e obj<\/code> \u304c\u5225\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u53c2\u7167\u3057\u305f\u3068\u3057\u307e\u3059\u3002<\/p>\n\n\n\n
obj = { name: 'bar' }<\/code><\/pre>\n\n\n\n
\u3059\u308b\u3068\u3001\u6700\u521d\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8 { name: 'foo' }<\/code> \u306f\u3069\u3053\u304b\u3089\u3082\u53c2\u7167\u3055\u308c\u306a\u304f\u306a\u3063\u305f\u305f\u3081\uff08\u4f7f\u3044\u305f\u304f\u3066\u3082\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u305b\u3093\uff09\u3001\u5fc5\u8981\u306a\u3044\u3068\u5224\u65ad\u3055\u308c\u3001\u3069\u3053\u304b\u3057\u3089\u306e\u30bf\u30a4\u30df\u30f3\u30b0\u3067\u30e1\u30e2\u30ea\u4e0a\u304b\u3089\u524a\u9664<\/strong>\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002\uff08\u3053\u306e\u6a5f\u80fd\u3092\u3001\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30b7\u30e7\u30f3<\/a>\u3068\u8a00\u3044\u307e\u3059\uff09<\/p>\n\n\n\n
\u3053\u308c\u306b\u5bfe\u3057\u3066\u300c\u5f31\u3044\u53c2\u7167<\/strong>\u300d\u306f\u3001\u53c2\u7167\u3067\u306f\u3042\u308b\u3051\u308c\u3069\u3082\u3001\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306b\u3088\u308b\u524a\u9664\u5bfe\u8c61\u3068\u306a\u308b\u53c2\u7167\u3067\u3059\u3002\u3064\u307e\u308a\u3001\u305d\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306f\u3044\u305a\u308c\u30e1\u30e2\u30ea\u4e0a\u304b\u3089\u524a\u9664\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n
2. JavaScript \u3067\u300c\u5f31\u3044\u53c2\u7167\u300d\u3092\u6271\u3046<\/h2>\n\n\n\n
JavaScript \u3067\u300c\u5f31\u3044\u53c2\u7167<\/strong>\u300d\u3092\u4f5c\u6210\u3059\u308b\u306b\u306f\u3001WeakRef<\/a> \u3068\u3044\u3046\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n\n\n\n
2-1.\u300c\u5f31\u3044\u53c2\u7167\u300d\u3092\u4f5c\u6210\u3059\u308b<\/h3>\n\n\n\n
\u3042\u308b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u5909\u6570 obj<\/code> \u306b\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u308b\u3068\u3057\u307e\u3059\uff08\u666e\u901a\u306e\u300c\u53c2\u7167\u300d\u3067\u3059\uff09\u3002<\/p>\n\n\n\n
let obj = { name: \"foo\" }\n<\/code><\/pre>\n\n\n\n
\u3053\u306e obj<\/code> \u3092\u5f15\u6570\u306b\u3057\u3066\u3001WeakRef \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002<\/p>\n\n\n\n
const weakRef = new WeakRef(obj)<\/code><\/pre>\n\n\n\n
\u5143\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306b\u5bfe\u3059\u308b\u300c\u5f31\u3044\u53c2\u7167<\/strong>\u300d\u3092\u4fdd\u6301\u3057\u305f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u3067\u304d\u307e\u3057\u305f\u3002<\/p>\n\n\n\n
\u3053\u306e\u5f8c\u3001obj<\/code> \u304c\u5225\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u53c2\u7167\u3057\u305f\u3068\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n
obj = { name: 'bar'}<\/code><\/pre>\n\n\n\n
\u3059\u308b\u3068\u3001\u5143\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8 { name: 'foo'}<\/code> \u306f\u3001\u300c\u5f31\u3044\u53c2\u7167<\/strong>\u300d\u306f\u3042\u308b\u3082\u306e\u306e \u666e\u901a\u306e\u300c\u53c2\u7167<\/strong>\u300d\u306f\u306a\u304f\u306a\u308a\u307e\u3059\u306e\u3067\u3001\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306b\u3088\u308b\u524a\u9664\u5bfe\u8c61\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n
2-2. \u53c2\u7167\u5148\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u53d6\u5f97\u3059\u308b<\/h3>\n\n\n\n
\u53c2\u7167\u5148\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u53d6\u5f97\u3059\u308b\u306b\u306f\u3001WeakRef \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e deref<\/a> \u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3044\u307e\u3059\u3002\u53c2\u7167\u5148\u304c\u65e2\u306b\u524a\u9664\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f undefined<\/code> \u3092\u8fd4\u3057\u307e\u3059\u306e\u3067\u3001\u53c2\u7167\u5148\u304c\u524a\u9664\u3055\u308c\u305f\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u306b\u3082\u4f7f\u7528\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n
weakRef.deref()<\/code><\/pre>\n\n\n\n
3. \u304a\u308f\u308a\u306b<\/h2>\n\n\n\n
\u5b9f\u969b\u306b\u4f7f\u3046\u6a5f\u4f1a\u306f\u3001\u3042\u307e\u308a\u306a\u3044\u306e\u3067\u306f\u306a\u3044\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n\n\n\n
<\/p>\n\n\n\n
4. \u53c2\u8003<\/h2>\n\n\n\n