{"id":14349,"date":"2019-06-24T09:00:04","date_gmt":"2019-06-24T00:00:04","guid":{"rendered":"https:\/\/www.agent-grow.com\/self20percent\/?p=14349"},"modified":"2019-06-18T08:40:37","modified_gmt":"2019-06-17T23:40:37","slug":"lets-use-map-in-js","status":"publish","type":"post","link":"https:\/\/www.agent-grow.com\/self20percent\/2019\/06\/24\/lets-use-map-in-js\/","title":{"rendered":"\u3010JavaScript\u3011\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3088\u308a\u4fbf\u5229\u304b\u3082\uff01\uff1f Map \u3092\u4f7f\u3063\u3066\u307f\u3088\u3046\uff01"},"content":{"rendered":"<h1>\u4eca\u56de\u306f JS \u3067\u306f\u3042\u307e\u308a\u4f7f\u308f\u308c\u3066\u3044\u306a\u3044\u3001Map \u306e\u3054\u7d39\u4ecb<\/h1>\n<p>JavaScript \u3067\u9023\u60f3\u914d\u5217\u306e\u3088\u3046\u306a\u3001\u30ad\u30fc\u3068\u5024\u306e\u30da\u30a2\u3092\u899a\u3048\u3055\u3048\u308b\u3068\u304d\u3001<br \/>\n\u57fa\u672c\u7684\u306b\u306f\u7686\u3055\u3093\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f7f\u3044\u307e\u3059\u3088\u306d\uff1f<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u611f\u3058\u3067\u3002<\/p>\n<pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nconst obj = {\n  hoge: \u2019fuga\u2019\n};\n\nconsole.log(obj.hoge); \/\/ =\uff1e fuga \u3068\u51fa\u529b\u3055\u308c\u308b\n\ndelete obj.hoge \/\/ =\uff1e obj.hoge \u304c\u524a\u9664\u3055\u308c\u308b\n<\/pre>\n<p>JavaScript \u3067\u306f\u3088\u304f\u898b\u308b\u5f62\u306a\u306e\u3067\u3059\u304c\u3001<br \/>\n\u30ad\u30fc\u3068\u5024\u306e\u30da\u30a2\u3092\u4f5c\u308a\u305f\u3044\u3068\u304d\u306b\u306f\u3053\u306e\u65b9\u6cd5\u3057\u304b\u7121\u3044\u3068\u601d\u3063\u3066\u307e\u305b\u3093\u304b\uff1f<\/p>\n<p>\u5b9f\u306f\u3001\u3042\u307e\u308a\u77e5\u3089\u308c\u3066\u3044\u307e\u305b\u3093\u304c\u3001\u3053\u3046\u3044\u3063\u305f\u3053\u3068\u3092\u3059\u308b\u305f\u3081\u306e\u624b\u6bb5\u3068\u3057\u3066\u3001<br \/>\nMap \u3068\u3044\u3046\u3082\u306e\u3082\u5b58\u5728\u3057\u3066\u3044\u308b\u306e\u3067\u3059\uff01<\/p>\n<p>\u4eca\u65e5\u306f\u3001\u305d\u3093\u306a Map \u306e\u3054\u7d39\u4ecb<\/p>\n<p>\u203b \u3044\u3064\u3082\u306e\u3001\u3068\u3066\u3082\u53c2\u8003\u306b\u306a\u308b MDN \u306e\u30da\u30fc\u30b8\u306f\u5148\u306b\u8cbc\u3063\u3066\u304a\u304d\u307e\u3059\u306d\u3002<\/p>\n<p>https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Map<\/p>\n<h1>Map \u3063\u3066\u3069\u3046\u3084\u3063\u3066\u4f7f\u3046\u306e\uff1f<\/h1>\n<p>\u4f8b\u3048\u3070\u3001\u5148\u307b\u3069\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u4f8b\u3092 Map \u3067\u3084\u308b\u3068\u3001\u3053\u3093\u306a\u611f\u3058<\/p>\n<pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nconst map = new Map();\nmap.set(\u2019hoge\u2019, \u2019fuga\u2019);\n\nconsole.log(map.get(\u2019hoge\u2019)); \/\/ =\uff1e fuga \u3068\u51fa\u529b\u3055\u308c\u308b\n\nmap.delete(\u2019hoge\u2019); \/\/ =\uff1e hoge \u30ad\u30fc\u3068\u5024\u306e\u30da\u30a2\u304c\u524a\u9664\u3055\u308c\u308b\n<\/pre>\n<p>\u6700\u521d\u306b Map \u3092\u751f\u6210\u3057\u3066\u3044\u308b\u3068\u3053\u308d\u304c\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u306d\uff01<\/p>\n<p>map \u3078\u306e\u5024\u306e\u8ffd\u52a0\u306f <code>map.set(\u30ad\u30fc, \u5024)<\/code> \u3067\u3001<br \/>\n\u5024\u3092\u53d6\u308a\u51fa\u3059\u306e\u306f <code>map.get(\u30ad\u30fc)<\/code> \u3068\u3001\u308f\u304b\u308a\u3084\u3059\u3044\u611f\u3058\u3067\u3059\u3002<br \/>\ndelete \u3082\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u5834\u5408\u306f delete \u6f14\u7b97\u5b50\u3068\u3044\u3046\u3042\u307e\u308a\u898b\u6163\u308c\u306a\u3044\u3082\u306e\u3092\u4f7f\u3063\u3066\u3044\u307e\u3057\u305f\u304c\u3001<br \/>\n\u3053\u3061\u3089\u3067\u306f map \u306b delete \u30e1\u30bd\u30c3\u30c9\u304c\u3042\u308b\u306e\u3067\u3001\u305d\u308c\u3092\u547c\u3093\u3067\u3042\u3052\u308c\u3070\u826f\u3044\u3068\u3044\u3046\u308f\u304b\u308a\u3084\u3059\u3055\u3067\u3059\u3002<\/p>\n<h1>Map \u3060\u3068\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3088\u308a\u4f55\u304c\u3044\u3044\u306e\uff1f<\/h1>\n<p>\u6b63\u76f4\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u4e8b\u8db3\u308a\u308b\u306a\u3089\u3001Map \u306a\u3093\u3066\u4f7f\u308f\u306a\u304f\u3066\u3082\u826f\u304f\u306a\u3044\uff1f\u3068\u601d\u3063\u3066\u307e\u305b\u3093\u304b\uff1f<br \/>\n\u78ba\u304b\u306b\u305d\u3046\u306a\u306e\u3067\u3059\u304c\u3001Map \u306e\u65b9\u304c\u8272\u3005\u306a\u9762\u3067\u300c\u3061\u3087\u3063\u3068\u4fbf\u5229\u300d\u306a\u3093\u3067\u3059\u3088\u306d\u3002<br \/>\n\u305d\u3053\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n<h2>\u30ad\u30fc\u306e\u5b58\u5728\u78ba\u8a8d\u304c\u7c21\u5358<\/h2>\n<pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nconst obj = {\n  hoge: false\n};\n\nif(obj.hoge) {\n  \/\/ \u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5024\u304c false \u306a\u306e\u3067\u3001obj.hoge \u306b\u5024\u306f\u3042\u308b\u304c\u3053\u3053\u306f\u5b9f\u884c\u3055\u308c\u306a\u3044\n  console.log(\u2019obj.hoge \u306f\u5024\u304c\u3042\u308b\u3088\uff01\u2019)\n}\n\n\nconst map = new Map();\nmap.set(\u2019hoge\u2019, false);\n\nif(map.has(\u2019hoge\u2019)) {\n  \/\/ \u3069\u3093\u306a\u5024\u304c\u683c\u7d0d\u3055\u308c\u3066\u3044\u3066\u3082\u30ad\u30fc\u306e\u5b58\u5728\u78ba\u8a8d\u306b\u306f\u5f71\u97ff\u3057\u306a\u3044\u306e\u3067\u3001\u3053\u3053\u306f\u5b9f\u884c\u3055\u308c\u308b\n  console.log(\u2019map \u306b\u306f hoge \u304c\u3042\u308b\u3088\uff01\u2019)\n}\n<\/pre>\n<p>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u30ad\u30fc\u306e\u5b58\u5728\u78ba\u8a8d\u3092\u3059\u308b\u5834\u5408\u306f\u3001\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5024\u306b\u3088\u3063\u3066\u6761\u4ef6\u5f0f\u304c\u610f\u56f3\u3057\u306a\u3044\u6319\u52d5\u3092\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<br \/>\n\u304d\u3061\u3093\u3068\u66f8\u3051\u3070\u3053\u3046\u3044\u3063\u305f\u554f\u984c\u306f\u56de\u907f\u3067\u304d\u307e\u3059\u304c\u3001\u3088\u304f\u3084\u308b\u6761\u4ef6\u5224\u5b9a\u306a\u306e\u3067\u3001\u3044\u3061\u3044\u3061\u8003\u3048\u308b\u306e\u3081\u3093\u3069\u304f\u3055\u3044\u3067\u3059\u3088\u306d\u2026<\/p>\n<p>\u4e00\u65b9 Map \u3067\u3042\u308c\u3070\u3001has \u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3048\u3070\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5024\u306b\u3088\u3089\u305a\u3001\u30ad\u30fc\u304c\u5b58\u5728\u3059\u308b\u304b\u3069\u3046\u304b\u304c\u5224\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n<h2>forEach \u304c\u7c21\u5358\u306b\u4f7f\u3048\u308b<\/h2>\n<pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nconst map = new Map();\nmap.set(\u2019hoge\u2019, \u2019hogehoge\u2019);\nmap.set(\u2019fuga\u2019, \u2019fugafuga\u2019);\nmap.set(\u2019piyo\u2019, \u2019piyopiyo\u2019);\n\nmap.forEach(function(v){\n  console.log(v);\n  \/\/ hogehoge\n  \/\/ fugafuga\n  \/\/ piyopiyo\n});\n<\/pre>\n<p>\u5168\u3066\u306e\u30ad\u30fc\u3092\u62fe\u3063\u3066\u3044\u304d\u305f\u3044\u3068\u304d\u306b\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u306f for&#8230;in \u306a\u3069\u3092\u4f7f\u3063\u3066\u66f8\u304f\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<br \/>\n\u66f8\u3051\u306a\u304f\u306f\u306a\u3044\u306e\u3067\u3059\u304c\u3001object.keys \u304b\u3089\u30ad\u30fc\u3060\u3051\u306e\u30ea\u30b9\u30c8\u3092\u4f5c\u3063\u3066\u2026\u307f\u305f\u3044\u306a\u3053\u3068\u3092\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u306e\u3067\u3059\u306d\u3002<br \/>\n\u307e\u305f\u3053\u308c\u3082\u3001\u3071\u3063\u3068\u4f7f\u3044\u305f\u3044\u6a5f\u80fd\u306a\u3060\u3051\u306b\u3001\u6bce\u56de\u8003\u3048\u308b\u306e\u306f\u3061\u3087\u3063\u3068\u30e1\u30f3\u30c9\u30a6\u3002<\/p>\n<p>\u4e00\u65b9\u3001Map \u3092\u4f7f\u3063\u3066\u304a\u3051\u3070\u3001Map \u306b\u5bfe\u3057\u3066 forEach \u3092\u305d\u306e\u307e\u307e\u4f7f\u3048\u308b\u306e\u3067\u3001<br \/>\n\u30b9\u30c8\u30ec\u30b9\u30d5\u30ea\u30fc\u3067\u8981\u7d20\u3092\u53d6\u308a\u51fa\u3057\u3066\u3044\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<h2>\u30ad\u30fc\u306b\u3069\u3093\u306a\u5024\u3067\u3082\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b<\/h2>\n<pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nconst key1 = {};\n\nconst map = new Map();\nmap.set(key1, \u2019hogehoge\u2019);\n\nconsole.log(map.get(key1)) \/\/ =\uff1e hogehoge\n<\/pre>\n<p>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u30ad\u30fc\u306b\u8a2d\u5b9a\u3067\u304d\u308b\u306e\u306f\u3001\u6587\u5b57\u5217\u304b\u3001\u307e\u305f\u306f Symbol \u3068\u547c\u3070\u308c\u308b\u3082\u306e\u3060\u3051\u306a\u306e\u3067\u3059\u304c\u3001<br \/>\nMap \u3067\u306f\u3069\u3093\u306a\u3082\u306e\u3067\u3082\u30ad\u30fc\u3068\u3057\u3066\u8a2d\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u4e0a\u306e\u4f8b\u306e\u3088\u3046\u306b\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u30ad\u30fc\u306b\u3057\u3066\u3057\u307e\u3046\u3053\u3068\u3060\u3063\u3066\u3067\u304d\u308b\u306e\u3067\u3059\uff01<br \/>\n(\u305d\u308c\u304c\u3069\u3093\u306a\u3053\u3068\u306e\u5f79\u306b\u7acb\u3064\u306e\u304b\u306f\u5206\u304b\u308a\u307e\u305b\u3093\u304c)<\/p>\n<h1>\u6a5f\u4f1a\u304c\u3042\u308c\u3070 Map \u3082\u4f7f\u3063\u3066\u307f\u3066\u306d<\/h1>\n<p>\u3061\u306a\u307f\u306b\u3001Map \u305d\u306e\u3082\u306e\u306f\u30012019\/06\/17 \u73fe\u5728\u306f IE \u3068 Edge \u3067\u306f\u4f7f\u7528\u3067\u304d\u306a\u3044\u305d\u3046\u3067\u3059\u3002<\/p>\n<p>https:\/\/caniuse.com\/#search=map<\/p>\n<p>\u30d6\u30e9\u30a6\u30b6\u5074\u3067\u4f7f\u3046\u3068\u304d\u306f\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u306d\u3002<\/p>\n<p>\u4eca\u307e\u3067\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u4f5c\u3063\u3066\u3044\u305f\u9023\u60f3\u914d\u5217\u304c\u3001\u5272\u3068\u7c21\u5358\u306b\u64cd\u4f5c\u3067\u304d\u308b\u5f62\u3067\u4f5c\u308c\u308b Map\u3002<br \/>\n\u662f\u975e\u3068\u3082\u4f7f\u3063\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u306d\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4eca\u56de\u306f JS \u3067\u306f\u3042\u307e\u308a\u4f7f\u308f\u308c\u3066\u3044\u306a\u3044\u3001Map \u306e\u3054\u7d39\u4ecb JavaScript \u3067\u9023\u60f3\u914d\u5217\u306e\u3088\u3046\u306a\u3001\u30ad\u30fc\u3068\u5024\u306e\u30da\u30a2\u3092\u899a\u3048\u3055\u3048\u308b\u3068\u304d\u3001 \u57fa\u672c\u7684\u306b\u306f\u7686\u3055\u3093\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f7f\u3044\u307e\u3059\u3088\u306d\uff1f \u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u611f\u3058\u3067\u3002 const [&hellip;]<\/p>\n","protected":false},"author":15,"featured_media":14366,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[10],"tags":[45],"class_list":["post-14349","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tech","tag-javascript"],"jetpack_featured_media_url":"https:\/\/www.agent-grow.com\/self20percent\/wp-content\/uploads\/2019\/06\/850c7612116999490846136e772ab7fd-2.png","jetpack_shortlink":"https:\/\/wp.me\/p7Bq4F-3Jr","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/posts\/14349","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/comments?post=14349"}],"version-history":[{"count":0,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/posts\/14349\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/media\/14366"}],"wp:attachment":[{"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/media?parent=14349"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/categories?post=14349"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.agent-grow.com\/self20percent\/wp-json\/wp\/v2\/tags?post=14349"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}